Watching you in this video it has come to me that Apple was the original mainstream DIY home personal computer company, where you could mod it, add things, do as you like.. engineers to the layman, everyone could figure it out. There were Apple / Mac clubs across the country and world. IBM was the 'business machine' company, where a technician would work on the systems and nobody in the office knew any better. Kind of crazy the direction Apple has gone over the years, where they make it about impossible to repair a newer Apple / Mac product yet just about any IBM compatible PC is fair game. Pretty crazy how things change over time.
I think _Altair_ claimed the "original DIY home pc" position, bit the IBM PC actually had some of it too, as they actually published full schematics. It's part of how the PC got so big so fast, everything was either "standard", or semi-"standard".
@@absalomdraconis thing is, Apple if still here, as is the IBM compatible PC. The reference was look at how the world flip flops, Apple WAS a club computer, diy community, became a mainstream brand. Ask 100 8 year olds what an Altair is today,. Ask the same kids who Apple is. That's where i was going with that.
Reminds me of power supply lab when I was in tech school. We were setting up for the lab experiments, then we heard a loud POP from one table, saw a big puff of smoke. The three instructors made their way over to the two now red-faced classmates and several second-year students peeked around the corner from the TV lab next door. Fortunately the cap didn't grenade, just the can came off cleanly like in the video, and there was paper EVERYWHERE.The consensus was that it was an old cap that had decided to give up.
I was an instructor in computer engineering technology at a community college in the early 90's. Once during a lab the students were working and I was doing some paperwork when suddenly there was a loud BANG. Looked up and saw a guy with a sheepish look and shaking his hand. He had taken on of the (thankfully very small) caps we were using for the lab and stuck it directly into the AC outlet. Yeesh!
@@bairfamilyfarm1336 The Flyback is running at a much higher frequency. The Power supply inside the monitor runs at 50Hz and is just by the neck of the monitor :)
I have an easy suggestion: Try a shielded RCA cable for the video signal. That may not solve the shaky image issue, but it may help reduce interference.
Yeah, seams some kind of electromagnetic interference, probably picked and carried into the monitor by the video cable, which may not be enough shielded. My guess is that the original apple 2c signal output is slightly lower than the 2e, and so more susceptible to interferences. Personally i would confirm that hooking the monitor input stage to an oscilloscope in order to see if there is some kind of ac intermodulated in the video signal.
Hi some apple and C64 does that shake here in Australia ( 240v 50hz ), many times it was fixed with 3 or 4 turns of the kitchen / food foil wrap C64 and Amiga tv modulator had that issue as well, wrap in foil then get out the black electrical tape to make it look neat - these days i would use heat shink cable if the foil wrap worked
@@Epictronics1 On the C64 and Amiga the cable to the monitor, if that did not solve it then a few people would wrap the power supply cables For the Apple 2c and 2e it was the monitor data / signal cable I am not sure if anyone mentioned to try using the RF output to see if it is any more stable Simply shielding the outer cable may solve issues, in cases where there is still a problem you may have to resort to slicing open the cable and insulate each signal wire separately as they get "cross-talk" between pins 1-2-3 etc rather than interference overall from say refrigerator / ac fan / washing machine We still have one of those "rabbit" tv / video extenders at home, basically it sits between aerial and tv or video player and tv, it then rebroadcasts the signal and you can pick it up on a second or 3rd tv in the home - with a simple upright fan on in the tv room, all other tv's show a ghosted image, when the washing machine is has waves, on spin dry the signal is lost. My in laws rear tv is still analog - when the left side neighbour is mowing the lawn they get ghosting
Has everyone forgotten how transformers work? Two coils of wire wrapped around an iron core? The two coils are magnetically coupled? It sure seems like the //c transformer is not magnetically shielded. If that is true the transformer is likely inducing the wobble in the deflection yoke. Also remember the //c transformer has no switch on it so it is always connected to the line when it is plugged in. Even when the //c is off the transformer is still magnetized. So repeat your lab power supply experiment and make sure the transformer is unplugged.
Yeah, we could power the display too with external power to see if that makes a difference. There is some metalwork around the transformer, but I couldn't tell if it's enough shielding
I greatly enjoyed this episode! Your camera work is exceptional. Weird issues make for entertaining content. Looking forward to all your future videos.
Looks like some kind of mains interference causing jitter on the horizontal sync signal. I checked my IIc with my osmelloscope and couldn't see any jitter on its output, so I suspect it's most likely in the monitor. However, mine is using a modern power supply that I made myself using a Meanwell "medical grade" switching power supply module, so it has a very clean DC input. If you want to check it for yourself, set the trigger to video mode and adjust the trigger level down until it locks onto the negative going horizontal sync pulse. Then zoom out until you can see several vertical refresh periods (I set mine for 10ms/div), and if you see any horizontal blurring or movement in the positive spikes of the active video period, that would indicate there's jitter on the signal.
Maybe the weird cap was a bipolar capacitor? Because there don't seem to be polarity markings on the board, and the polarised capacitor clearly didn't like whatever was put at it's legs.
Absolutely. How would anyone install a polarized capacitor without polarity markings? Unless it's a super-cheap Chinese capacitor with no markings at all, just a plain aluminum can
@@Epictronics1 that's weird. I thought that as long as the voltage is same or higher, you were safe. I have one of those monitors to recap soon, do you happen to have a list of caps I could borrow? ;)
@@Epictronics1 It might be a lower maximum current rating. This is something most people don't need to worry about but it matters in some demanding applications.
That transistor in the apple 2c power regulator module could be causing problems. As you have essentially put very long legs on it. Those legs could be functioning as an AM transmitter. Not to mention capacities losses that will affect the power supply characteristic.
Maybe check nets for AC ripple, ie, set DMM to AC instead of DC. Maybe a metal partition between CRT and Apple][, or put a foil coated box over the CRT.
AZERTY is normal french keyboard layout. All european Apple IIe have this switch on the bottom from factory to switch the keyboard layout and the display output between american and the respective alternative character set. My german Apple IIe has the same switch with the difference it gives the german QWERTZ layout and the ÄÖÜ keys. French layout has some terrible quirks for anyone not used to it. The number row has the special characters and you need the shift key to type numbers. And far worse for my taste, the M key is right next to L instead of the bottom row. Main mod to the IIe would be the enhancement kit for me that upgrades the ROMs and the CPU to make the IIe more IIc compatible. And I have a Apple II VGA card in mine, nice project based on a Raspi Pico.
@@Epictronics1 No, the VGA card only grabs the graphics signal from the bus and converts it to VGA to get a crystal clear video output. Also it bypasses the character ROMs so the switch to another language set needs an application or POKE commands to switch the output in the Pico software.
I have a classic Apple 2e colour monitor. It has released smoke but the display still emits a dot - so it's probably a problem with the deflector circuitry.
I had a lot ofo trouble with interference on my Apple //c and it 9" monitor and after weeks of messing around unsuccessfully I took a punt and replace the BNC video cable. It fixed it. It was the cheap video cable all along. I dont know if you have tried different cables or not but if you haven't, it might be worth a check.
Ok, thanks for sharing. I'm using the original Apple cable that came with the //c. I have tried with another cable, but that made it worse! I'll try with a really high quality cable. Only trouble is how to know witch one is really good
The original "Samwha" capacitor that you didn't know what it was is a bipolar electrolytic capacitor with very low ESR designed for high frequencies. It's probably used in the deflection circuitry, much in the same way the 3.9 or 4.5 uF cap in a compact Macintosh is. A normal bipolar electrolytic is NOT suitable for this application, the high frequency will cause them to heat up and detonate, as such happened in your case. Nobody manufacturers those high frequency bipolar electrolytic capacitors anymore, because the only real use case for them was in analog CRT circuitry. When CRTs went away, so did they. Film capacitors generally will work as a replacement, I prefer film caps rated for microwave frequencies. The problem with them though is they're physically a lot larger and can be hard to fit in place of the old electrolytic part. You **might** be able to get away with using two high frequency rated low ESR polarized electrolytic capacitors and put them anode to anode or cathode to cathode to make a biploar capacitor. I don't know if such capacitors exist, but they're bound to be less of a unicorn than the old bipolar types that aren't made anymore.
You may try measuring the vertical and horizontal synch pulses with the IIc board connected to the IIc display. Make sure the ground wire of the oscilloscope probes is short, otherwise you won't be able to interpret the measurements. I bet you will find both synch pulses are a little jittery. This may have to do with reflections from impedance mismatches, or power supply fluctuations on the driver chips, etc. It may be possible to solve it by adding filter capacitors from the synch line(s) to ground, in the order of a couple of hundred pF. You may check one of my videos, called "Perfect restoration of a 1977 Commodore PET 2001, Part 6" (can't add the URL here, or UA-cam will think this comment is spam), where I went through this hole process. Good luck!
Wow, great restoration! It gave me some inspiration to bring out my PET too and restore it. I'll watch the rest of the restoration later today. The Apple //c horizontal and vertical sync signal are coming out from IOU chip pin 39. I soldered one 470pF ceramic cap between pin 39 and pin 1(ground) but no difference. I added 1nF but still no difference unfortunately.
@@Epictronics1 Thanks! The horizontal oscillation in your case seems to be very low amplitude and quite high frequency. So maybe you can try a physically smaller 100pF capacitor still, just to rule out a problem there (the frequency response of smaller capacitors is different)? You can also scope out the signal to see if it is solid. If you try the 100pF capacitor, it may be worth to make sure the ground connection is as close as possible, otherwise the inductive reactance of a long lead may ruin the effect at these higher frequencies.
I'll be honest, brownish red goop, it LOOKS like transmission fluid, but that's mostly dyed, and obviously nothing to do with whatever exploded. I did however have a TV (CRT) that blew something, I was too young to remember what at the time, but I remember it smelling extremely metallic, and after opening it up to try to fix it, it had a very similar substance all over everything. Looking up the part however, there is a plastic layer inbetween the electrodes, which is often colored a number of colors, and given the size of the electrodes, I wouldn't be at all surprised if these plastics are just straight liquidated and sprayed out during failure, it would also explain why denatured alcohol works on it, as methanol tends to weaken plastic bonds as it's commonly used to make plastics and create polymers, basically, if it is plastic, you're thinning it by introducing methanol; but I wonder how it would have reacted to acetone.
Also FYI, you cant just add leads to a switching transistor like that if it never had them originally, those long wires wrapped around will increase the inductance, and also cause ringing in the switching circuits, therefore creating EMI. Not saying thats causing your problem here, but it can contribute when its least expecting to.
My Italian - and my British - Apple //e have the same switch to switch between US/British/Italian character sets. It was factory indeed. I'm curious now, have you confirmed the issue happens on different monitors too? I can test my monitor on both the //e and the //c if you want. Though my monitor has the switching power supply. The shaking seems to be 50Hz - so wondering whether it could be some ground loop somewhere? Can you try powering up the monitor from your bench power supply? It's a 12V supply. You need to lift the fuse and you can clip the positive there - leaving the fuse in place for safety. Obviously with no mains connected. That would remove the linear power supply inside the monitor from the equation.
Yes, I have tried all combinations with 3 different Apple //c and two //c displays. I'm not super knowledgeable about ground loops but from my understanding, this is not the problem, because the display and computer are connected to the same power outlet. I'll try with external power, thanks
@@Epictronics1 Yes, powering from the same socket should help but ground loops can be tricky sometimes! It does look 50Hz flickering to me though. Uhm... interesting! I'll check with my Apples when I get to the monitor.
@@tony359 Ok, thanks! I tried adding a 68, 470 and 1000pF cap between pin 39 and ground on the IOU chip (sync) but it didn't make a differens. Next I'm gonna try to feed switch mode power to the display.
The "S" is in reality § a common symbol on modern European computers/code pages. It is called "Section sign" or "paragraph" used mostly for Laws and academic works. It is kinda weird it shows up as a character in the French code page, but the Apple was a bit weird back then. Before they went over to the Dark Side.
If the jitter issue is caused by a crystal you could try replacing the crystal with an oscillator. They have the caps built in and output a nice clean frequency just by connecting vcc and gnd. Find an oscillator of the same frequency, wire up 5V and gnd and connect the output to where the crystal was connected then test and see if the jitter is gone. If not you will need to check all the parts in the horizontal sync section.
Thanks. I read somewhere that these crystals could be difficult to find. Do you think it would work if I pull the crystal and inject a clock with a signal generator?
Unrelated to anything, but i took a 15v usb-c to barrel jack cable and cut the jack off and wired it to a 7 pin female din like the power supply has, and use that instead of that crazy huge power supply that comes with the 2c.
Seen this screen jitter countless times when an NTSC (60hz) IIc or IIe is used with an Apple 9" PAL (50Hz) monitor. It seems that while the PAL monitor can display the NTSC signal, it's just out of spec enough to cause the jitter.
The 14mhz was slightly fluctuating on the 2c. Is that the case on the 2e? Maybe the Commorodore is just a better monitor overall and can tolerate it. If it's not fluctuting on the 2e maybe that's it.
You can also look into H/V sync signal shape and play around with trigger level on a scope, also you can enable long persistence on a scope to see if the signal is not jittery. The other thing I thought is that C64 has a good Schmitt buffer that triggers more stable than the 2c monitor
The fluctuation is caused by the portable oscilloscope.Probably from the software trigger or the way it samples the signal. That crystal is most likely OK.
if i not mistaking that apple 2c have giltchly feed back to cable and it can cause shaking letters i think one way to get around this is bypassing origin video port and run it to ic chip controls and back to port it should fixed it i think Adrian make video of 8808 book that ic chip he did to book have make it better and if you do that to apple 2c it should get rid of shaking picture save your self a headache
Has the blown bipolar capacitor been in the horizontal deflection circuit? Then it will have been a non polarized high frequency capacitor capable to carry a high ripple current. "NPHF" could be an indicator. You cannot use "any" standard or low esr capacitor to replace these. If the original SAMHWA is still OK just leave it in for the time until you find appropriate replacement.
@@Epictronics1 Yes, I'm aware of - your replacement cap was quite small. I searched your first video about this monitor and saw that the original SAMWHA was an NPHF type (assumably non polarized, high frequency). These types are quite bulky. I also had to learn the hard way when repairing Atari SM124s. Conventional electrolytics, even low esr, are not fit for the extreme load and run hot and may, as in your case, explode. With my SM124 I had luck and noticed that the replacement I bought run hot within short time.
Worth testing the monitor with something else, such as an SNES or anything else you have that has a composite video out. This will further help narrow down the issue.
I did one more test off-camera. The JVC color display in the thumbnail is hooked up to the //c. The image was shaky with that display too. I'll go through my stuff and see what else I can find to test with.
Is it possible that the //c issue with the monitor //c is magnetic interference? Maybe try the //c further away from the monitor, and make sure the power brick is further away. The other possibility that comes to mind is a ground loop of some kind.
This looks like a ground loop to me. I don't know how the screen really is connected, but you may want to remove the ground connection from the signal cable on one side. The ground loop may be caused by having one ground connection through the power cable, and one through the signal cable.
@@Epictronics1 i was talking about signal ground, not earth groud from the outlet (thogh that may also come into play) Easy to try and maybe rule out that solution though ;)
This could be electromagnetic interference from the transformers in the monitor / IIc psu? try a shielded video cable or shielding between the monitors transformer and the tube.
The transistor having extended legs like that (with the cable) is actually a problem because those long wires will have extra inductance compared to how the circuit was designed.
OK, I'll see if I can find a new transistor. However, I have tested the display with another //c that didn't have the transistor bodge. The image was still shaky
@@Epictronics1 Sure, just thought I'd mention that it's not unknown for switch-mode regulators to become unstable if they have extra inductance in the wrong spot.
@@skonkfactory If the inductance was between the rectifier and the feedback it would matter. Here I think it would just fry the transistor before affecting the regulation. Plus the frequency is fairly low.
Um yeah that cap is a bipolar cap, not polarised so no wonder it blew up hehe! You can make an electrolytic bipolar cap by joining 2 polarised caps together. Solder the minus legs together and put the plus legs into the board.
@@Epictronics1 was the original bipolar too? I can't see a cap exploding due to frequency. Maybe the actual voltage on the board was higher than the rated cap you put in? I think I know what that is. Might be a special 4.7uF 50V or 63V low impedance cap used in the flyback circuit. I have a bunch of them here made by CAPXON that I bought to fix some Commodore 108x monitors. They are yellow and pretty big 16mm diameter by 30mm long but only 4.7uF 63V. On mine it says BP so it's Bipolar too.
That the original PSU produces seemingly synchronized but larger wobble when nearby is very definitely sus! Please try to play with any kind of video modes or picture settings to see if there is any correlation. IIRC Apple II has low and high resolution modes (40/80 columns?), do they wobble exactly identically? It's probably a humongous waste of time, but if someone go through the footage frame by frame at max resolution and try to ascertain the wobble frequency with and without the PSU close it may possibly help. The exact frequency may hint at where the wobble is coming from. Perhaps analyze it with some sort of camera image stabilizer software? Here's another wild, probably incorrect guess: what if H-SYNC signal processing works but just marginally? Perhaps IIe might have a stronger driver or something? And IIc is not driving it hard enough to signal to fall exactly in time? Look more closely at the shape and level of the leading/falling edge in max magnification. It may be subtle. Try to poke at H-sync the various points, not just the display connector.
@@Epictronics1 I don't know of any info on the inet but I have experienced similar problems on contemporary equipment when I ran a repair shop in the late 90's, There could be a potential difference between the ground rails that may cause this issue especially if the laptop is powered by a external brick as there is in effect no common ground between devices. you could try to add extra grounding to see if this effects the issue.
What’s different about the cap is that it has to have specific characteristics at frequencies higher than 10 kHz (it’s a part of the horizontal deflection circuit). My mono IIc monitor ate quite a few normal NP caps before I fitted the correct cap, which looks similar to yours.
That's the original Deoxit can or at least it looks like it, the same Deoxit can I got in the UK 6+ years ago had the same issue with the straw... so Deoxit seemingly got rid of there horrible new can, to go back to the same exact less horrible older can 🤦♂... I haven't bought Deoxit since, as its hella expensive in the UK and the dispenser meant more than half of it got wasted with every application. Shifting picture, weak/failing transistors or IC's in the image circuitry, or the circuit is very susceptive to transformer/rectification (60/120Hz) "noise" as you showed with the power brick proximity, if your Lab PSU is analogue transformer/rectification noise might still be there... my two cents
@@SianaGearz Servisol Super 10, but annoyingly they have been bought out and I think its now sold under the Kontakt Chemie Brand "Kontakt Super 10", I have used other electronic switch/contact cleaners even WD-40 do one and they all seem to do the job. I can't really say there was a night and day difference between them and Deoxit... maybe Deoxit is better over time and gentler on certain plastics etc... but thankfully have had no such issues with the Super 10 to date. If memory servers the WD-40 contact cleaner dispenser (Ironically similar Deoxit's most recent fumbled dispenser) with its fixed straw is a bit too bulky to get into certain places but was otherwise fine too.
IPA is 99%, denatured ethanol is 92%, and what really does the job is the... water content. This goo dissolves in water, but not in alcohol. Next time just try to use demineralized water.
The mess in the PSU is in fact Rifa guts that wasn't cleaned up and has had a chance to dry for a few decades. It's just dodgy repair work up to and including the old flux on the back of the board. This is what happens when you take your machine to a hack instead of a real repair person. What you have there my friend is disgusting.
8:25 Not that I'm trying to contradict you, but your theory doesn't .make sense to me. AZERTY was never a thing in Canada. It's only ever been QWERTY here. I've lived in Québec all my life, and the only times I ever seen an AZERTY layout was on tourist's and immigrant laptops from France. I'm really puzzled by that keyboard too, but I would assume it's European from my perspective.
Just to make it clear... We have a few popular layouts over here. Among those are "French Canadian", "French Canadian Legacy" and "Canadian multilingual". All of which use QWERTY as a base layout for the letters. The only things that change is for the accents and other weird characters we use in french.
Do they really still add methanol into denatured alcohol at your end of the planet? Here they use 5% isopropyl alcohol, some very smelly but not very toxic ketone, and denatonium (bitrex). I mean why would you make it deadly on purpose if there's another way to make sure it won't be used for drinking.
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I understand why this channel is named "Epic-tronics". Even the caps go out in spectacular fashion!
Pretty epic mess in both machines lol
Watching you in this video it has come to me that Apple was the original mainstream DIY home personal computer company, where you could mod it, add things, do as you like.. engineers to the layman, everyone could figure it out. There were Apple / Mac clubs across the country and world. IBM was the 'business machine' company, where a technician would work on the systems and nobody in the office knew any better. Kind of crazy the direction Apple has gone over the years, where they make it about impossible to repair a newer Apple / Mac product yet just about any IBM compatible PC is fair game. Pretty crazy how things change over time.
I think _Altair_ claimed the "original DIY home pc" position, bit the IBM PC actually had some of it too, as they actually published full schematics. It's part of how the PC got so big so fast, everything was either "standard", or semi-"standard".
@@absalomdraconis thing is, Apple if still here, as is the IBM compatible PC. The reference was look at how the world flip flops, Apple WAS a club computer, diy community, became a mainstream brand. Ask 100 8 year olds what an Altair is today,. Ask the same kids who Apple is. That's where i was going with that.
Reminds me of power supply lab when I was in tech school. We were setting up for the lab experiments, then we heard a loud POP from one table, saw a big puff of smoke. The three instructors made their way over to the two now red-faced classmates and several second-year students peeked around the corner from the TV lab next door. Fortunately the cap didn't grenade, just the can came off cleanly like in the video, and there was paper EVERYWHERE.The consensus was that it was an old cap that had decided to give up.
I was an instructor in computer engineering technology at a community college in the early 90's. Once during a lab the students were working and I was doing some paperwork when suddenly there was a loud BANG. Looked up and saw a guy with a sheepish look and shaking his hand. He had taken on of the (thankfully very small) caps we were using for the lab and stuck it directly into the AC outlet. Yeesh!
@@EddieSheffield lol
it's the magnetic field of the power transformer in the monitor unit. You'll never get rid of the shaking unless you change that transformer.
it could be. But why only with the //c?
If that were the case, why isn't the flyback causing issues?
@@bairfamilyfarm1336 The Flyback is running at a much higher frequency. The Power supply inside the monitor runs at 50Hz and is just by the neck of the monitor :)
I have an easy suggestion: Try a shielded RCA cable for the video signal. That may not solve the shaky image issue, but it may help reduce interference.
The cable I'm using is the original cable that came with the //c. It may not be good enough for my noisy studio. I'll check
Yeah, seams some kind of electromagnetic interference, probably picked and carried into the monitor by the video cable, which may not be enough shielded. My guess is that the original apple 2c signal output is slightly lower than the 2e, and so more susceptible to interferences.
Personally i would confirm that hooking the monitor input stage to an oscilloscope in order to see if there is some kind of ac intermodulated in the video signal.
Hi some apple and C64 does that shake here in Australia ( 240v 50hz ), many times it was fixed with 3 or 4 turns of the kitchen / food foil wrap
C64 and Amiga tv modulator had that issue as well, wrap in foil then get out the black electrical tape to make it look neat - these days i would use heat shink cable if the foil wrap worked
@@georgemaragos2378 Very interesting. what are you shielding? the cable?
@@Epictronics1 On the C64 and Amiga the cable to the monitor, if that did not solve it then a few people would wrap the power supply cables
For the Apple 2c and 2e it was the monitor data / signal cable
I am not sure if anyone mentioned to try using the RF output to see if it is any more stable
Simply shielding the outer cable may solve issues, in cases where there is still a problem you may have to resort to slicing open the cable and insulate each signal wire separately as they get "cross-talk" between pins 1-2-3 etc rather than interference overall from say refrigerator / ac fan / washing machine
We still have one of those "rabbit" tv / video extenders at home, basically it sits between aerial and tv or video player and tv, it then rebroadcasts the signal and you can pick it up on a second or 3rd tv in the home - with a simple upright fan on in the tv room, all other tv's show a ghosted image, when the washing machine is has waves, on spin dry the signal is lost.
My in laws rear tv is still analog - when the left side neighbour is mowing the lawn they get ghosting
Has everyone forgotten how transformers work? Two coils of wire wrapped around an iron core? The two coils are magnetically coupled? It sure seems like the //c transformer is not magnetically shielded. If that is true the transformer is likely inducing the wobble in the deflection yoke. Also remember the //c transformer has no switch on it so it is always connected to the line when it is plugged in. Even when the //c is off the transformer is still magnetized. So repeat your lab power supply experiment and make sure the transformer is unplugged.
Yeah, we could power the display too with external power to see if that makes a difference. There is some metalwork around the transformer, but I couldn't tell if it's enough shielding
Maybe the suggestion is a good one, but your tone is a bit rude?
@@uomoartificiale Try being polite in a different language. It's as much as I can do to order a beer, let alone a repair video.
@@markpitts5194 The vocabulary was perfect. The sentiment was a little harsh. AFAIK, sentiment doesn't need translation.
I greatly enjoyed this episode! Your camera work is exceptional. Weird issues make for entertaining content. Looking forward to all your future videos.
Thanks!
Looks like some kind of mains interference causing jitter on the horizontal sync signal. I checked my IIc with my osmelloscope and couldn't see any jitter on its output, so I suspect it's most likely in the monitor. However, mine is using a modern power supply that I made myself using a Meanwell "medical grade" switching power supply module, so it has a very clean DC input.
If you want to check it for yourself, set the trigger to video mode and adjust the trigger level down until it locks onto the negative going horizontal sync pulse. Then zoom out until you can see several vertical refresh periods (I set mine for 10ms/div), and if you see any horizontal blurring or movement in the positive spikes of the active video period, that would indicate there's jitter on the signal.
That sounds like a great next step to test
Maybe the weird cap was a bipolar capacitor? Because there don't seem to be polarity markings on the board, and the polarised capacitor clearly didn't like whatever was put at it's legs.
Absolutely.
How would anyone install a polarized capacitor without polarity markings?
Unless it's a super-cheap Chinese capacitor with no markings at all, just a plain aluminum can
It is a bipolar cap, yeah
The cap we blew up was bipolar too. There is something else different with that unidentified cap
@@Epictronics1 that's weird. I thought that as long as the voltage is same or higher, you were safe. I have one of those monitors to recap soon, do you happen to have a list of caps I could borrow? ;)
@@Epictronics1 It might be a lower maximum current rating. This is something most people don't need to worry about but it matters in some demanding applications.
The horizontal sync is slightly out of phase between the PCB and Screen raster.
That transistor in the apple 2c power regulator module could be causing problems. As you have essentially put very long legs on it. Those legs could be functioning as an AM transmitter. Not to mention capacities losses that will affect the power supply characteristic.
I'll try to find a new transistor. Thanks
Maybe check nets for AC ripple, ie, set DMM to AC instead of DC.
Maybe a metal partition between CRT and Apple][, or put a foil coated box over the CRT.
Maybe putting that film cap upright (one leg through the hole and a short jumper wire to reach the other lead) fits better.
AZERTY is normal french keyboard layout. All european Apple IIe have this switch on the bottom from factory to switch the keyboard layout and the display output between american and the respective alternative character set. My german Apple IIe has the same switch with the difference it gives the german QWERTZ layout and the ÄÖÜ keys.
French layout has some terrible quirks for anyone not used to it. The number row has the special characters and you need the shift key to type numbers. And far worse for my taste, the M key is right next to L instead of the bottom row.
Main mod to the IIe would be the enhancement kit for me that upgrades the ROMs and the CPU to make the IIe more IIc compatible. And I have a Apple II VGA card in mine, nice project based on a Raspi Pico.
also replacing the power supply with a modern pico one and improving efficiency
I'm considering the VGA card too. Are there any Apple // games that take advantage of VGA?
@@Epictronics1 No, the VGA card only grabs the graphics signal from the bus and converts it to VGA to get a crystal clear video output. Also it bypasses the character ROMs so the switch to another language set needs an application or POKE commands to switch the output in the Pico software.
I would check the internal power supply on the display. Possibly some ground issue with the transformer. The fault looks like a magnet field problem.
I have a classic Apple 2e colour monitor. It has released smoke but the display still emits a dot - so it's probably a problem with the deflector circuitry.
I had a lot ofo trouble with interference on my Apple //c and it 9" monitor and after weeks of messing around unsuccessfully I took a punt and replace the BNC video cable. It fixed it. It was the cheap video cable all along. I dont know if you have tried different cables or not but if you haven't, it might be worth a check.
Ok, thanks for sharing. I'm using the original Apple cable that came with the //c. I have tried with another cable, but that made it worse! I'll try with a really high quality cable. Only trouble is how to know witch one is really good
One of the few channels I can stand to watch solder/desolder. You have great technique. What brand paint markers are you using to mark the caps?
Thanks. Those pens are made by Pilot
The original "Samwha" capacitor that you didn't know what it was is a bipolar electrolytic capacitor with very low ESR designed for high frequencies. It's probably used in the deflection circuitry, much in the same way the 3.9 or 4.5 uF cap in a compact Macintosh is.
A normal bipolar electrolytic is NOT suitable for this application, the high frequency will cause them to heat up and detonate, as such happened in your case.
Nobody manufacturers those high frequency bipolar electrolytic capacitors anymore, because the only real use case for them was in analog CRT circuitry. When CRTs went away, so did they.
Film capacitors generally will work as a replacement, I prefer film caps rated for microwave frequencies. The problem with them though is they're physically a lot larger and can be hard to fit in place of the old electrolytic part.
You **might** be able to get away with using two high frequency rated low ESR polarized electrolytic capacitors and put them anode to anode or cathode to cathode to make a biploar capacitor. I don't know if such capacitors exist, but they're bound to be less of a unicorn than the old bipolar types that aren't made anymore.
Thanks. So, the film cap seems to be a good solution
“This machine is a bit weird and I don’t mind”. 🤣
Weird is interesting, right?🤣
You may try measuring the vertical and horizontal synch pulses with the IIc board connected to the IIc display. Make sure the ground wire of the oscilloscope probes is short, otherwise you won't be able to interpret the measurements. I bet you will find both synch pulses are a little jittery. This may have to do with reflections from impedance mismatches, or power supply fluctuations on the driver chips, etc. It may be possible to solve it by adding filter capacitors from the synch line(s) to ground, in the order of a couple of hundred pF. You may check one of my videos, called "Perfect restoration of a 1977 Commodore PET 2001, Part 6" (can't add the URL here, or UA-cam will think this comment is spam), where I went through this hole process. Good luck!
Thanks for sharing! I'll definitely check out that video!
Wow, great restoration! It gave me some inspiration to bring out my PET too and restore it. I'll watch the rest of the restoration later today. The Apple //c horizontal and vertical sync signal are coming out from IOU chip pin 39. I soldered one 470pF ceramic cap between pin 39 and pin 1(ground) but no difference. I added 1nF but still no difference unfortunately.
@@Epictronics1 Thanks! The horizontal oscillation in your case seems to be very low amplitude and quite high frequency. So maybe you can try a physically smaller 100pF capacitor still, just to rule out a problem there (the frequency response of smaller capacitors is different)? You can also scope out the signal to see if it is solid. If you try the 100pF capacitor, it may be worth to make sure the ground connection is as close as possible, otherwise the inductive reactance of a long lead may ruin the effect at these higher frequencies.
@@thebyteattic I actually did check with the scope. I can't see any ripple or spikes. I'll try with a smaller cap next. Thanks!
Might be the video cable not being properly screened? If it's not a proper coaxial cable.
I use the original cable that came with the //c
@@Epictronics1 could be worth trying some alternatives. Just to make sure it's not a factor.
I'll be honest, brownish red goop, it LOOKS like transmission fluid, but that's mostly dyed, and obviously nothing to do with whatever exploded. I did however have a TV (CRT) that blew something, I was too young to remember what at the time, but I remember it smelling extremely metallic, and after opening it up to try to fix it, it had a very similar substance all over everything. Looking up the part however, there is a plastic layer inbetween the electrodes, which is often colored a number of colors, and given the size of the electrodes, I wouldn't be at all surprised if these plastics are just straight liquidated and sprayed out during failure, it would also explain why denatured alcohol works on it, as methanol tends to weaken plastic bonds as it's commonly used to make plastics and create polymers, basically, if it is plastic, you're thinning it by introducing methanol; but I wonder how it would have reacted to acetone.
Also FYI, you cant just add leads to a switching transistor like that if it never had them originally, those long wires wrapped around will increase the inductance, and also cause ringing in the switching circuits, therefore creating EMI. Not saying thats causing your problem here, but it can contribute when its least expecting to.
Ok, I'll see if I can find a new transistor and replace it. Thanks
I love the Apple IIe
My Italian - and my British - Apple //e have the same switch to switch between US/British/Italian character sets. It was factory indeed.
I'm curious now, have you confirmed the issue happens on different monitors too? I can test my monitor on both the //e and the //c if you want. Though my monitor has the switching power supply.
The shaking seems to be 50Hz - so wondering whether it could be some ground loop somewhere? Can you try powering up the monitor from your bench power supply? It's a 12V supply. You need to lift the fuse and you can clip the positive there - leaving the fuse in place for safety. Obviously with no mains connected. That would remove the linear power supply inside the monitor from the equation.
Yes, I have tried all combinations with 3 different Apple //c and two //c displays. I'm not super knowledgeable about ground loops but from my understanding, this is not the problem, because the display and computer are connected to the same power outlet. I'll try with external power, thanks
@@Epictronics1 Yes, powering from the same socket should help but ground loops can be tricky sometimes! It does look 50Hz flickering to me though. Uhm... interesting! I'll check with my Apples when I get to the monitor.
@@tony359 Ok, thanks! I tried adding a 68, 470 and 1000pF cap between pin 39 and ground on the IOU chip (sync) but it didn't make a differens. Next I'm gonna try to feed switch mode power to the display.
When did this channel become Epicsplosion?
this really seems like some sort of EMI issue, conducted or radiated.
The "S" is in reality § a common symbol on modern European computers/code pages. It is called "Section sign" or "paragraph" used mostly for Laws and academic works. It is kinda weird it shows up as a character in the French code page, but the Apple was a bit weird back then. Before they went over to the Dark Side.
I would probe the horizontal sync circuitry. It appears to be highly sensitive to interference.
If the jitter issue is caused by a crystal you could try replacing the crystal with an oscillator. They have the caps built in and output a nice clean frequency just by connecting vcc and gnd. Find an oscillator of the same frequency, wire up 5V and gnd and connect the output to where the crystal was connected then test and see if the jitter is gone. If not you will need to check all the parts in the horizontal sync section.
Thanks. I read somewhere that these crystals could be difficult to find. Do you think it would work if I pull the crystal and inject a clock with a signal generator?
@@Epictronics1 Yes you can inject the clock from a generator. What frequency is the crystal?
Unrelated to anything, but i took a 15v usb-c to barrel jack cable and cut the jack off and wired it to a 7 pin female din like the power supply has, and use that instead of that crazy huge power supply that comes with the 2c.
Could it be an issue with the signal cable and lack of shielding?
Seen this screen jitter countless times when an NTSC (60hz) IIc or IIe is used with an Apple 9" PAL (50Hz) monitor. It seems that while the PAL monitor can display the NTSC signal, it's just out of spec enough to cause the jitter.
Indeed, AZERTY is a French layout. QWERTZU would be the German layout, although I think it's also used as alternative (to AZERTY) on French keyboards.
If you replace every part of that Apple //c, is it the same //c? 🤔
The 14mhz was slightly fluctuating on the 2c. Is that the case on the 2e? Maybe the Commorodore is just a better monitor overall and can tolerate it. If it's not fluctuting on the 2e maybe that's it.
You're right. I'll compare the two. Thanks
You can also look into H/V sync signal shape and play around with trigger level on a scope, also you can enable long persistence on a scope to see if the signal is not jittery.
The other thing I thought is that C64 has a good Schmitt buffer that triggers more stable than the 2c monitor
@@SergiuszRoszczyk yeah I was wondering about that as well.
The fluctuation is caused by the portable oscilloscope.Probably from the software trigger or the way it samples the signal. That crystal is most likely OK.
@@thargoid666 probably, but the other crystal wasn't fluctuating.
if i not mistaking that apple 2c have giltchly feed back to cable and it can cause shaking letters i think one way to get around this is bypassing origin video port and run it to ic chip controls and back to port it should fixed it
i think Adrian make video of 8808 book that ic chip he did to book have make it better and if you do that to apple 2c it should get rid of shaking picture save your self a headache
Some capacitors that look fine have drifting values
Given that these monitors take a standard composite video singnal. Have you tried another source? Like a DVD player or Raspberry pi etc.
Well, it works perfectly with the //e. I'll try with some other stuff.
Has the blown bipolar capacitor been in the horizontal deflection circuit? Then it will have been a non polarized high frequency capacitor capable to carry a high ripple current. "NPHF" could be an indicator. You cannot use "any" standard or low esr capacitor to replace these. If the original SAMHWA is still OK just leave it in for the time until you find appropriate replacement.
Interesting, thanks for sharing. I checked and there is one guy selling 3.9uF NPHF caps on eBay. The cap I blew was bi-polar but not HF
@@Epictronics1 Yes, I'm aware of - your replacement cap was quite small. I searched your first video about this monitor and saw that the original SAMWHA was an NPHF type (assumably non polarized, high frequency). These types are quite bulky. I also had to learn the hard way when repairing Atari SM124s.
Conventional electrolytics, even low esr, are not fit for the extreme load and run hot and may, as in your case, explode. With my SM124 I had luck and noticed that the replacement I bought run hot within short time.
Worth testing the monitor with something else, such as an SNES or anything else you have that has a composite video out. This will further help narrow down the issue.
I did one more test off-camera. The JVC color display in the thumbnail is hooked up to the //c. The image was shaky with that display too. I'll go through my stuff and see what else I can find to test with.
Is it possible that the //c issue with the monitor //c is magnetic interference? Maybe try the //c further away from the monitor, and make sure the power brick is further away.
The other possibility that comes to mind is a ground loop of some kind.
Yeah, I did some thinking after I had finished the video. This could be a ground loop issue for sure
This looks like a ground loop to me. I don't know how the screen really is connected, but you may want to remove the ground connection from the signal cable on one side.
The ground loop may be caused by having one ground connection through the power cable, and one through the signal cable.
The display and Apple //c are connected to the same outlet. Shouldn't that eliminate the risk of ground loop issues?
@@Epictronics1 i was talking about signal ground, not earth groud from the outlet (thogh that may also come into play)
Easy to try and maybe rule out that solution though ;)
This could be electromagnetic interference from the transformers in the monitor / IIc psu? try a shielded video cable or shielding between the monitors transformer and the tube.
I'll give that a try
The transistor having extended legs like that (with the cable) is actually a problem because those long wires will have extra inductance compared to how the circuit was designed.
OK, I'll see if I can find a new transistor. However, I have tested the display with another //c that didn't have the transistor bodge. The image was still shaky
@@Epictronics1 Sure, just thought I'd mention that it's not unknown for switch-mode regulators to become unstable if they have extra inductance in the wrong spot.
@@skonkfactory If the inductance was between the rectifier and the feedback it would matter. Here I think it would just fry the transistor before affecting the regulation. Plus the frequency is fairly low.
As for card suggestions: a Phasor sound card.
I'll check it out. Thanks
Was there any shielding in the 2c or monitor looks like rf interference
There is some metalwork around the transformer. The display is shielded on all sides except the top of the display where the vent grill is.
A safety cap brand with worse explosions than RIFA? Crazy.
Um yeah that cap is a bipolar cap, not polarised so no wonder it blew up hehe! You can make an electrolytic bipolar cap by joining 2 polarised caps together. Solder the minus legs together and put the plus legs into the board.
The blown up cap was bi-polar too. The original cap has been identified now, it was a high frequency cap
@@Epictronics1 was the original bipolar too? I can't see a cap exploding due to frequency. Maybe the actual voltage on the board was higher than the rated cap you put in? I think I know what that is. Might be a special 4.7uF 50V or 63V low impedance cap used in the flyback circuit. I have a bunch of them here made by CAPXON that I bought to fix some Commodore 108x monitors. They are yellow and pretty big 16mm diameter by 30mm long but only 4.7uF 63V. On mine it says BP so it's Bipolar too.
That the original PSU produces seemingly synchronized but larger wobble when nearby is very definitely sus!
Please try to play with any kind of video modes or picture settings to see if there is any correlation. IIRC Apple II has low and high resolution modes (40/80 columns?), do they wobble exactly identically?
It's probably a humongous waste of time, but if someone go through the footage frame by frame at max resolution and try to ascertain the wobble frequency with and without the PSU close it may possibly help.
The exact frequency may hint at where the wobble is coming from.
Perhaps analyze it with some sort of camera image stabilizer software?
Here's another wild, probably incorrect guess: what if H-SYNC signal processing works but just marginally?
Perhaps IIe might have a stronger driver or something?
And IIc is not driving it hard enough to signal to fall exactly in time?
Look more closely at the shape and level of the leading/falling edge in max magnification. It may be subtle.
Try to poke at H-sync the various points, not just the display connector.
I think we should be able to see the shaking frequency with a scope. I'll try that next
I think your problem is a ground loop issue, can you test if there is a voltage difference between the ground of the monitor and the computer.
Interesting. I never had any problems with ground loops. Is there a good write up or video about this issue?
@@Epictronics1 I don't know of any info on the inet but I have experienced similar problems on contemporary equipment when I ran a repair shop in the late 90's, There could be a potential difference between the ground rails that may cause this issue especially if the laptop is powered by a external brick as there is in effect no common ground between devices. you could try to add extra grounding to see if this effects the issue.
@@dannyarnold9823 I'll try that. Thanks!
Nope, French Canadian is QWERTY. Definitively French.
Or maybe they used that keyboard for both markets?
I just assumed they used the same kb for both markets. Maybe some French and Canadian Apple // users could chime in here.
That’s definitely a non polar cap as it has NP marked on it. SAMHWA is obviously some sort of copycat name of SAMWHA.
Yes, but the cap I blew up was non polar too. There is something else to that SAMHWA cap
What’s different about the cap is that it has to have specific characteristics at frequencies higher than 10 kHz (it’s a part of the horizontal deflection circuit). My mono IIc monitor ate quite a few normal NP caps before I fitted the correct cap, which looks similar to yours.
AZERTY is definitely French. And funny how you mentioned QWERTZ because that's a German (language) thing.
That's the original Deoxit can or at least it looks like it, the same Deoxit can I got in the UK 6+ years ago had the same issue with the straw... so Deoxit seemingly got rid of there horrible new can, to go back to the same exact less horrible older can 🤦♂... I haven't bought Deoxit since, as its hella expensive in the UK and the dispenser meant more than half of it got wasted with every application. Shifting picture, weak/failing transistors or IC's in the image circuitry, or the circuit is very susceptive to transformer/rectification (60/120Hz) "noise" as you showed with the power brick proximity, if your Lab PSU is analogue transformer/rectification noise might still be there... my two cents
Yes, that Lab PSU has a transformer. I'll try again with a switch mode PSU
Is there a EU or UK product similar to Deoxit D5?
@@SianaGearz Servisol Super 10, but annoyingly they have been bought out and I think its now sold under the Kontakt Chemie Brand "Kontakt Super 10", I have used other electronic switch/contact cleaners even WD-40 do one and they all seem to do the job. I can't really say there was a night and day difference between them and Deoxit... maybe Deoxit is better over time and gentler on certain plastics etc... but thankfully have had no such issues with the Super 10 to date. If memory servers the WD-40 contact cleaner dispenser (Ironically similar Deoxit's most recent fumbled dispenser) with its fixed straw is a bit too bulky to get into certain places but was otherwise fine too.
IPA is 99%, denatured ethanol is 92%, and what really does the job is the... water content. This goo dissolves in water, but not in alcohol. Next time just try to use demineralized water.
lol. Thanks for sharing. I'll try with water next time
The mess in that power supply looks like nicotine stains.
Since I once was a heavy smoker, I can assert you, that condensed nicotine would produce a really evenly distributed layer.
No way that much nicotine would have entered a power supply, it's a closed box in a closed box.
The mess in the PSU is in fact Rifa guts that wasn't cleaned up and has had a chance to dry for a few decades. It's just dodgy repair work up to and including the old flux on the back of the board. This is what happens when you take your machine to a hack instead of a real repair person. What you have there my friend is disgusting.
Well, not anymore. The PSU and case is nice and shiny again :)
Afaik, "azerty" is just french, not french canadian, french canadians actually use another form of "qwerty"
if logic doesn't work, brute force might...
8:25 Not that I'm trying to contradict you, but your theory doesn't .make sense to me. AZERTY was never a thing in Canada. It's only ever been QWERTY here. I've lived in Québec all my life, and the only times I ever seen an AZERTY layout was on tourist's and immigrant laptops from France.
I'm really puzzled by that keyboard too, but I would assume it's European from my perspective.
Just to make it clear... We have a few popular layouts over here. Among those are "French Canadian", "French Canadian Legacy" and "Canadian multilingual". All of which use QWERTY as a base layout for the letters. The only things that change is for the accents and other weird characters we use in french.
@@jeremiefaucher-goulet3365 Thanks for clarifying things.
Do they really still add methanol into denatured alcohol at your end of the planet? Here they use 5% isopropyl alcohol, some very smelly but not very toxic ketone, and denatonium (bitrex). I mean why would you make it deadly on purpose if there's another way to make sure it won't be used for drinking.
I read that info on Wiki. Maybe, it's outdated.
:)))))))