Dumpster Tektronix 475 Oscilloscope Repair - Part 1
Вставка
- Опубліковано 5 вер 2024
- This is an UNFINISHED video.
My lab is unusable at present and I'm not sure when I'll get around to finishing this, so thought I'd upload what I've got now.
Repair and teardown of a dumpster Tektronix 475
#Tektronix #Oscilloscope #Repair
Bitcoin Donations: 38y7DE8HEHNj8fGDtUr4PkCn9nWxiorvvy
Litecoin: MRnSifHf1jjgimgFq56YWXb3uo1iHdhg1R
Ethereum: 0x11AceA38DCA9DbFfB4F35f3F746af65F9dED28ce
Ripple: rBgnUKAEiFhCRLPoYNPPe3JUWayRjP6Ayg
I felt sad inside when this just abruptly ended like that
Likewise....................:-(
I need to see the fix on this one.
I was like... darn stripper... what do you need a another $1. The dance was bad, I admit it. Then starts looking like... huh... what the front door... yep... strip tease. Felt better than the... man... I wouldn't trust the admins tests results down under for the water unless you hired from Flint Michigan water company folks. I was actually thinking he was going to distill the water until I saw the magnetic line and act. Good times... unless the water is that bad. Better get on it fast!!! That's OK... the Tektronix and Military Manuals porn strip tease is typical of the damn... he's not going to fix it now. At least there's great information you can't find anywhere else due to legitimate water quality issues... like... what the pharma and sent us down the drain with China. Check out the latest or a "Kathy Loves Physics" YT'er if you feel sad. Her latest has some leads... wait... is it spelled leeds... got me spooked... or well have that already? It's not D-IX in the water at least and whatever else banned.
Thanks for the lead on the manual too: radionerds.com/images/b/ba/TM_11-6625-2735-24P.pdf
And another thank you sir: radionerds.com/images/8/80/TM_11-6625-2735-14-1.PDF
My grandfather was a technician writer for a lot of these old Tek scopes and other gear. Always makes me smile when I hear how much people appreciate those manuals. And think how apparently he wasn’t well liked by some of the engineers. Lol.
"Materiel" - not a typo! It's military speak for "equipment". Because modern militaries love their jargon.
Materiel comes from French and has been used to mean military equipment for over a century, now.
Yes, "materiel" is a very old term. The USAF has gone back and forth on that: Materiel Command was split into Systems Command and Logistics Command in the 70s, and then rejoined them in the 90s.
Yup, Materiel is the correct spelling and is still used today in the USAF. (Air Materiel Command). :)
That really brings back the memories. I used a 475 every day at work for over 10 years, from about 1979 to 89.
The coax delay line is not for delay sweep, it's so you can see the trigger point.
Ahhh Tektronics 475. I spent a few years connected to one of these. Good times!
Would love to see part 2 of this repair. I have one of these scopes with a timebase A sweep problem I'm working on. Keep safe!
When you repair something I feel very productive for the day.
I love these scopes. I just restored/repaired a Tek 475A (same scope, but 250 Mhz bandwidth and some minor differences). These scopes can have multiple issues as mine did, but they are just so cool looking. Just as a note, all transistors are socketed, you can pull them right out. Same with most of the ICs. My scope was also missing the 5V rail and the -15V rail was all over the place, bouncing between --21V and -25V. The missing 5V rail was caused by a bad main filter cap, the -15V rail was caused by a faulty regulating transistor Q1478. The opamps U1454 and U1464 are also failure points, I just replaced them with NE5532's since finding originals is a pain. All 6 of the main filter caps definitely need replacing as those are the originals in there; two of mine were reading as resistors - they had failed pretty badly. Mine also had a no sweep issue, the trace was just a stationary dot on the CRT. Caused by a faulty JFET in the sweep generator - Q1010. A common fault as well. The tant caps do fail in these, in fact one blew out right in my face while I was probing the power supply. Very similar to the pop you heard when you turned your scope on. I've replaced a few of them, but certainly not all, as there are over 100 throughout the scope. Check the tants on the power supply at the very least. Also the vertical volts/div controls and the timebase controls operate a rotating drum which pushes on mechanical switch contacts, they almost always have to be cleaned, as well as the pots for the trigger level controls. There was a lot more that I had to do but honestly that would be several paragraphs and really what can you expect for a scope that's almost 50 years old. There is an endless amount of info out there for the 465/475's. Amazing machines really
Thanks. Yeah quite concerned with all the tants and other caps. Makes be hesitant to spend the time on it, because Murphy will ensure there will be a boat load of problems
@@EEVblog2 - Yeah there usually is with these scopes, they're a work in progress. I didn't believe you when you had said a long time ago that a good scope can be had for around $50 on Ebay, but that's eventually what I found. A completely dead 475A and a dead Tek TDS 420A. $60 shipped each. And if it's completely dead it's almost always the power supply, which is repairable. A good multimeter and some basic knowledge, research, and a little time and it's not too difficult. I just got done with mine a few weeks ago, if I can do it anyone can - imgur.com/a/SH6hLrt
Edit - Actually I probably need to sell these things, running out of room. Hoarding old, broken test equipment I bought from Ebay and repairing it seems to be my issue now...
Hoping for a follow up Dave! Looks like a interesting repair with the detailed manual and all.
Old test gear repairs are the best!Make it work Dave!
While you wait for your lab you can ship this off to Mr. Carlson's Lab and we can all watch a 2 hour video with 4 minutes of content and 35 minutes of ads for his schematics you can buy on patreon.
4 minutes of content only? Show me that one!
Ditto that! That guy is over the top. I un subbed him a long time ago. Couldnt take it anymore.
@@herbertsusmann986 I still watch his videos sometimes but I have to watch them at 2x speed, and if it becomes clear that the whole video is specifically designed around using his probes and testers then I just stop watching. He does a lot of good work and deserves to make money as much as anyone else, but he really needs to work on his presentation. Dave here at EEVBlog sells plenty of stuff too but he doesn't come across like a shill for himself.
This is my primary oscilloscope! Rescued it from the dump and just replaced a few tantalum capacitors. Works like a charm!
I have a similar one and I never figured out what that awesome metal delay knob with the crazy multiturn scale actually does. Seems to do nothing. Is mine broken or does it only work in certain modes I've never used?
" Hey...Mr Hart (Jones)... When you gonna finish eh?! " I want part 2, pretty please. :)
Im so excited that you are creating a detailed troubleshooting tour of this scope! I actually own one of these. I bought it broken at the local flea market for just a few bucks, but I haven't opened it up to fix it yet. With this video series, I'm hoping that I'll be able to get it working! Im sorry you have to deal with your office getting flooded, I'm sure it's really setting you back. I hope your office gets cleaned up and mold free soon!
Used to have one of those back in 1976 - 1978 in the back of my trusty MK2 Hillman Avenger (!!) @ Ferranti as a computer Field Service Engineer. Then I had a BRAND NEW one when I stopped commuting two ways across the Pennines from Bradford to Wythenshawe daily and moved to DEC in Leeds the same year as that scope also as a FS Engineer. GREAT scopes. All the Textronic kit I ever used was fantastic gear. So reliable! They must have really abused that to bugger it and break the knob bezel. Mine were bounced around in the back of various vehicles for years and were practically mint when I left FS and moved to Sales.
That scope was the best in our avionics shop in the 70's. There were constant tug of wars over who got to use it instead of the old tube filled beasts.
Heh, we still fight over scopes at my Avionics company. But mainly fighting with the people from "test equipment" who want to reclaim your scope.
Nothing like vintage Tek. Absolute top of the line vack in the day. I had a 475A on my bench back in the early 80s.
I have one of those. Mine is rated for 300MHz. It also has the DM module on top, though that has a bit of a problem these days. I've had the thing for several decades now and I still love it! Works great and it comes in handy quite a bit. Of course, it's a bit of a beast and these days I tend to use my Tektronix TDS220 LCD scope. It works pretty well and is a lot lighter and easier to carry around.
Looking forward to more on this. That scope is a great scope. Hope we can see a bit of a fixer-upper on it, if its possible. Thanks Dave and hope the lab gets back up and running soon.
My first (real) job was calibrating these in 1977. Really need to gradually turn them on, caps dry out over time, dust will create arc paths, some arcs are forever damaging. Need to open it up, smell it, clean it, check the primary supply impedance, remove the un-replaceable vertical output Hybrid, can't remember ever turning a unit on without a CRT (many other memories about those CRT's), did turn on ever newly born instrument with a Variac, slowly bringing up the AC, watching the current. Every instrument would be "burned in" for 24 hours, a many reversed tantalum cap would explode under the thermal stress. One poignant memory is being shocked on my left arm by the -2KV cathode supply, as I leaned on the back chassis, with the safety cover off, I felt that "snap". Whats the hand signed name on the Tested By label on the inner front bezel above the CRT? Ironically I don't own one.
I think it still deserves to be on the main channel despite being unfinished.
Awsome. I didn't even watch it yet. This scope means a lot to me. I got one as a gift when I was 14 and I didn't even know what it was.
....... Dry large cap pad with arc carbon at 6:20 under right leg of 5w resistor.
You missed what I thought was a fun thing about these - note all the transistors are socketed. The chips and ASICs too (like the vertical pre-amps with the big fins) but actual individual transistors are socketed. They must have been expensive!
It's awesome watching you fix things I could never fix. Have you ever thought about doing a tutorial series on how to do basic troubleshooting and ramp it up towards advanced? I know I'd watch them all if it was paced right.
About time to continue with this repair, Dave! 😁
Best front panel ever.
Love the old two channel analog scopes, this is one of the ones I used to rely on. I actually drive around with a 15meg two channel in my car, I really need to clean my car out.
Great Scott, we all know who EB, who have signed this cap, is.
Anyway, that is one hell of a cliffhanger here. Where does the popping sound comes from? Will the scope be fixed or suffer more damage? You'll see in the next episode or in another space time continuum where the lab had not been flooded. Damn these quantiq weather butterflies.
Ironically, I spent last weekend w/ this exact same model on the bench, also w/ HV power supply problems (although thankfully, no arcing, just not enough voltage to drive the CRT). I just love the way these old scopes look on the bench (and no boot-up time), but I am dreading the nightmare that will be cap replacement. This definitely isn't the easiest device to service, since just getting the boards out of the chassis is quite the endeavor.
8 volts - yeah, I can just hear the 74-series TTL chips screaming 🤬
"EB" says the grafitti... if this turns out to be an extended april's fool video with "this old tony" levels of time travelling, I won't be mad.
This video takes me back to the early Seventies and beyond when I used to repair and calibrate these wonderful Tek 'scopes as a technician in the US Army, so it's quite nostalgic for me. Oh yes, Materiel (spelled and pronounced that way on purpose) is a common expression in the US military for all sorts of military equipment. I suppose they spell it that way to differentiate it from material fabric. We used to call the tantalum capacitors jellybeans. By the way, I enjoy your videos immensely, in spite of your voice sounding like your nuts are caught in a vise. I've become used to it now. Cheers from across the big pond.
The delay line is NOT the delayed sweep, it allows one to see the trigger. The sweep has to have time to start when triggered, but the signal that caused the trigger would be long gone... By delaying the signal we can see the signal at the trigger time.
Never test and debug anything old by powering it on without checking inside first.. (unless you have mountains of scopes like Dave). Anyone buying a old scope off ebay should obey the prime directive of this channel *never turn something on before taking it apart* (at least to check a bit)
*For the excitement, and click bait, he likely wants something to come-a-gutsa in front of us all. What is life without the fun?
As a certain electronics youtuber once said "Don't turn it onnnn, take it aaaapppppaaaaarrrrrtttt!"
Well, at least check if old tantalums are inside and check if some already changed their colour..
Also, burned resistors and leaky capacitors are easy to check.
Nonsense. Did you see how MANY tantalum capacitors are in there? If there's a shorted one, yes, it will burn out a resistor when you turn it on, if it didn't do so when the last guy had it, but that's easier to find/repair than just shotgunning the whole instrument. People who routinely replace every electrolytic must not be aware that in many cases, an original cap from the 1970s will outlast a modern replacement. These days, the lifetime of an instrument is determined by the crappy capacitors available. In the past, when electronics was expensive, the notion of designing capacitors for a 5- or 10-year lifetime would have been absurd.
Besides, once you disassemble that beast to the level where you can replace all of the caps, and put it back together, the chances of NOT introducing new problems is approximately nil.
@@BrightBlueJim If someone really is 'into' restoration.. Yes, modern caps will outlast the old ones because such things as Nichicon UMV etc.. exist. Still, if a newbie wants 5-years of renewed use, standard el-caps will do fine. Quality restoration's are slower project's to be sure, but many newbies can restore these old beauties armed with just boat-anchor PDF's and a DMM (and capable of reading a few posts on EEVblog of course..). Also, some tagtant failures can burn far more than just a resistor.. they can cause a whole series of stresses and 'cascade failures' often making it damn-near impossible for a newbie to debug later. It should be noted, Dave's video's on this topic are to illustrate that good scopes, signal generator's, 5/6.5 digit DMM's and a lot of other stuff can be bought cheaply and repaired (if you're careful and take your time..)
We do not talk about some electrolytics, we talk about tantalum caps from 70s to 80s. And these terrible caps tend to fail by high numbers, I had instruments where about 30% of those caps were either shorted or had terrible leakage and/or very high resistance - i.d. 30% failure rate. Before even thinking about any trouble-shooting of those old instruments I replace all tantalums even before switching on. A dead short in the reference section can ruin your day..
Beautiful old style oscilloscope, not like the new oscilloscopes, all with digital electronics that cannot be repaired at all.
Giuseppe Maggio back when I was being paid to spend someone else's money I got a 200meg 4 channel digital scope. Hardly ever turned it on after the first week because I spent more time fiddling with the scope than reading waveforms. I actually drive around with a 15meg 2 channel analog in my car, don't leave home without it.
The delay line has nothing to do with the delayed sweep. The delay line delays the vertical signal before it goes to the CRT so you can see what you triggered on.
"Delayed sweep" is a somewhat ambiguous term. I think he was talking about the small delay that lets you see a bit before the trigger. A better term would be "delayed time base" (DTB).
@@autogolazzojr7950 Delayed sweep on a Tektronix scope is a mode where timebase B is delayed by the sweeptime of timebase A (often plus a fine adjustment on a seperate control); it does have a very specific meaning.
Looking forward to the next part! =D
You see this kind of thing all the time in retro-computing channels. Any time you get something 30 years old or more, always check the inside before you power it on. Old X/Y class capacitors in particular are famous for drying out and failing in a large puff of magic smoke. Tantalums also tend to fail rather spectacularly.
I've got a 465 scope which is the earlier version of that. Mine was purchased off ebay as a reconditioned unit in good condition. Nice scopes.
Not earlier - the 465 and 475 were both introduced at the same time and produced over the same period - from the late 1960s to mid-80s. The 465 was the 100 MHz workhorse, while the 475 was for people who needed higher performance (200 MHz for the 475, and 250 for the later 475A). If you didn't really need more than 100 MHz, the 465 was actually a better instrument, because it wasn't quite as close to the bleeding edge of the technology.
8.6V on the 5V rail I immediately thought of the TTL logic chips. You may be lucky though, depending on the family type LS, L, H etc it requires 9V or so to destroy them.
Peter Mortimore greetings, I was a broadcast video tech for 20 years, factory trained whenever the sales department wanted to pick up a new product as it was required. 1970s high end electronics are really a piece of art and design. Wouldn't be surprised if that high +5 vdc rail was because nothing was loading it down. Those items weren't being told to turn on. Maybe, nice to see someone else who knows these things
I feel the need to buy 1979 scope. Thank you for being optimistic
I've gotten quite a few 1970s scopes running in the last decade. They're relatively easy to work on because for the most part, they use standard parts that can still be bought. This got much worse in the 1980s, when everybody (Tek included) started using specialized ICs everywhere. Just make sure you can find a service manual online before buying anything.
such a sudden cut off is a bit how ya doin'
The era of hand drawn traces and service manuals.
But that manual is the military version. The original Tektronix manuals had two-color schematics! Black and light blue, although I can't remember exactly what blue was used for.
Very useful information! I have a Tek T932 that won't even power on at all, and the knobs for Channel 2 are missing. Hopefully some day I can fix it, or get it fixed.
Nice the 4XX Series is my Fave. Easy to repair, most parts are still able to get. Still have one 465. 468 was my fave.
Except for old units like this were the could be huge numbers of failed or failing parts
Whoo hoo, that mailing address is where I was born! And just a few year's after my birthday.
The slot for the second power switch was for an option that allowed the 'scope to run from DC power. The second switch turned on the inverter.
That coil of cable under the CRT is the trigger delay line so you can see your trigger.
Looks like the opamps U1464A & U1464B is blown. The opamps uses negative feedback to set the negative voltages. First thing to test. It may be that those opamps are not getting the correct power voltages creating a cascading effect. You may have to trace the opamp power rails back to the fault, most likely a capacitor is shorted.
So was I right?
Wait, no "see you next time"? this is outrageous
Checking back here to see if this video got finished. I have a 475A that doesn't seem to be synchronizing. The timing circuit may be a fault.
Stuck in XY mode? No worries! I mostly use my Tek 465M as a vector display when fixing early 80’s arcade PCBs...
Tek really owned the scope world back then!
Great video, waiting for Part II. :)
Scope makes a popping sound but Dave apparently has no interest in finding out where that is coming from. I would have taken the cover off the HV power supply and turned it on with the room lights off. Might see an arc.
I sometimes heard a similar 'tick' when my parents' toaster's thermal switch disengaged. (it was an oldie even then)
So it could simply mean that it's not sluggish in it's handling of overheating.
Nice multimeter probes!
Just got an untested 475A yesterday to play around with, just my luck!
Used that exact model for years and years while in the USAF.
Has a shorted filter in my 475, the blue Mallory cans did not age well, after a year of use another shorted.
Anyone seen Melodysheep's TIMELAPES OF THE FUTURE. Mindblowing!!!....Sorry off topic but Science....
It keeps getting suggested to me but I haven't watched it. Maybe I will now.
Well Worth the time, It will make your lifespan shink.. In a nice way....;-)
So what would you recommend to replace the Tantalum Capacitors with. I hate Tantalum Capacitors they should be removed from all new electronics that are being made today.
I think I can see a cracked solder joint on the filter cap on the right at 5:50.
An EEV cliffhanger! There's the old trick of turning out the lights to try and see where the arcing is happening.
I used to use one of them back in the late '70s when I worked at DEC.
Here is an oddball question that just occurred: is it feasible, or practical, to use a scope's own 1kHz probe calibration output as a "signal" of sorts to be injected into say audio circuits and followed along with the oscilloscope? Yes, I know it's a square wave, not all audio circuits might be happy with it, but other than that could this be done? Can this output be used as a "wave generator" in a pinch?
Problem with those pouches, is that they're great if you're constantly lugging the thing around, but if you've got it on your bench, it's inevitably in the way of whatever you're stacking on top of it. I remove them.
None of that tube rubbish, apart from the crt :D hope to see it fixed
Doh, yeah
had one of these
while working, great. but began to tilt on the pots and switches ... so changed to a digital Oscar
(missing the demos haha)
Got one :) working and very good condition :)
Dave, you got to show us more please.
Hey @EEVblog2 do you sell all these dumpster finds? I'm after a new scope. You seem to be very lucky with finiding Scopes, TV's, Computers, etc in dumpsters. All I find are half eaten nuggets, burgers and KFC. Are you camping outside some electronics wholsaler or something?
When you're through with that techtronic telescope what do you plan on doing with it? The reason I ask is I really could use a decent working scope.
At 4:30 in the board there has some very unique switches there, looks like pin comes from the other side and pushes the tabs to open the switch. What controls these? Button on front? Electromagnet? Looks different, kinda cool. at 8:40 in the schematic say regulating range selector, that just a reference to the line voltage input switch? Just seemed different. Last, I notice was 9:20 in, the trimmer pot, left had side has a melted corner on it. P.S. I was and am still somewhat looking for some kind of April fools thing to come out. Love me some Dave Jones.
Fiberglass shafts from the front panel. One of these was a bandwidth limit switch (limited bandwidth to I think 20 MHz, which made the trace sharper when you didn't need all that bandwidth), which I think is what the ones he points out do. Roughly similar to the fiberglass rod that connects the power pull knob on the front panel to the power switch itself, that he was so amused by. See that piece of twinaxial cable going up and left from the area of the switches? That's the output to the deflection amplifier.
Tek instruments from this era also had cam switches - the front panel knob turns a barrel about 3/4" diameter that runs most of the length of the PCB, and has cams that push those pins you see. This allowed for things like boosting the vertical gain at the 2 mv/div setting. Using cam switches meant that many things in the circuit could be changed without having to run wires all the way to the front panel.
I was a tech at Tek in the early 80s, and worked on hundreds of the 400-series 'scopes. Not really my favorite, as the 475 had a rather fat electron beam as a result of using an expansion mesh to magnify the deflection to achieve 250 MHz bandwidth. A slightly later version, the 475A, upped the bandwidth to 300 MHz with less use of beam expansion, by using improved electronics. But my favorite was the 456B, which had the cleanest step response of any scope I worked on, although only good to about 130 MHz (spec was 100 MHz).
Oops, 465B.
@@BrightBlueJim Thanks for reply. Was curios about them. Got me a tek 2213 60 Mhz . Some new caps in it. Main scope is Rigol MSO 4000. Was wondering about the switches was all, were different to me. Yea Dave like his big long control rods. Most are reliable but if one breaks it can be a bummer. Need me a 3d printer. I currently restore HF radios and such and could use a way to print out small plastic sprockets they use for the control shafts.
@@johncundiss9098 Sounds like the best use of a 3D printer I've heard of in some time. One thing that has always been difficult for hobbyists to do is custom parts in the fine control of the tuning dial.
The 2213 and 2215 were a result of a complete reboot at Tek, that began when B&K, Philips, Hitachi, and Kikusui started encroaching on Tek's turf - high-performance scopes. When 50 MHz and better scopes became available for half of Tektronix's prices, they developed the high-volume CRT production line, and re-thought things like cam switches, complicated metal chassis, and long fiberglass actuator rods, all of which contributed quite a lot to the production costs. The 2213/15 had most of their circuitry on a single PCB, a one-piece aluminum frame, and were designed so that the initial calibration could be semi-automated. And of course used the new high-volume CRTs, which were really quite good. I almost bought a 2213 brand new - it was the first Tek scope a young technician could afford - $1100. Now I have a 7704A with 7A26 vertical and 7B80/85 horizontal plugins, which I spent less then $200 on! "Coincidentally", this is what was on my bench at Tek. My main portable now is an HP 1725A (275 MHz with dual delayed timebases) that I refurbished. It's kind of a shame, but Tektronix 400 and 2400 series scopes have such a good reputation, they're hard to find at a decent price unless they need serious work (like this one).
Although the complicated assemblies were expensive to make, they were sturdy as Tonka trucks. I never saw a broken fiberglass shaft on a Tek product. Most damage was external, like broken knobs (again, like on Dave's unit) and bent metal shafts due to banging the instrument against things, or banging things into them. This was a testament to their ruggedness - people knew they didn't have to baby them, so many of them have had rough lives, and most still work.
@@BrightBlueJim Very true. Good info there. The2213 needed some new poly caps, Dave did video not to long ago on exact same ones. Otherwise works perfect. I also know the scope came from a TV repair shop and was on 10 hours a day every day for I have no clue how many years. Currently is my scope monitor to be sure my linear amplifier is being linear.
I have one of those, with a led multimeter at the top.
Did you put the Aussie 240v into the Yankee 120v device? That snap could be the transformer primary side having a dielectric breakdown.
At 5:00 you can see it's on 230V mode.
Thank you Indrek. So perhaps the high voltage transformer for the CRT is going. That snap sure sounds like a winding that is failing.
@@bertblankenstein3738 But even more likely (since it's snapping repeatedly), it's dust/dirt forming a bridge on the PCB in the high voltage section. While these scopes often had high voltage failures, actual component failures usually blew the fuse.
@@bertblankenstein3738 At 7:10 on the upper left corner you can see a neon bulb starts glowing prior to the bang. So yes, something is wrong with the high voltage supply as well. Hopefully not the transformer, because Dave won't go that far to replace it. Maybe just an overvoltage due to the overvoltage condition of the low voltage PSUs.
Maybe someone else had the unit in 120 mode while plugged in to 240. Regardless, we await the exciting conclusion.
Great Scott! Your went with 121GW for your multimeter's model number?
Never noticed that before, gave me a nice chuckle.
Okay, if nobody else will bite, I will: what does "121GW" mean to you?
7:25 Component center screen down a little split down middle.
Where is part 2? I have this scope in my basement with a bad transformer. I thought it had a toroidal transformer. Can you help?
I hope to see you resurrect the old scope.
All that electronics was pre-automated assembly. Probably taped up layout too. How did they get by?
I stuffed printed circuit boards for a company Grass Valley Group, Tektronix bought GVG....hand soldering, I actually really loved doing it...
@@leesa7489 I was just joking about getting by. I'm sure it was enjoyable. Many years ago, I installed and serviced machinery that did auto insert, practically at the dawn of automated assembly. It was pretty relaxed back in the day, ppl smoking and eating and drinking while they put stuff together. Not now. Everything approaches cleanroom conditions if it's not exactly cleanroom status.
Definitely hand-taped - in those days there was no layout software that could even DO curved traces.
I bet you thought oh the mode toggle switch is broken, but that is TOAST. No like if a rail is totally overvolting, very probably significant damage is done somewhere unless there was some sort of protection in the design.
7:11 you can see what popped in top left.
I think that is just a neon bulb lighting up. They used neon bulbs as clamps to overvoltage protection in high voltage circuits. So probably something is wrong with the high voltage supply as well.
Don't sweat any manual corrections, as even Fort Monmouth is now gone.
Dave...I have a 465B Tektronix Scope that I am working on. It looks nearly Identical to your Scope there. Problem - both Traces are too Short! It seems to be in the Horizontal Section but I can't find it nor can I seem to find any help with it online.
Wow! This one I know personally!
I use one of those at work!
What was "the big dumpster find" alluded to?
Never mind, I found it: ua-cam.com/video/YX0MJjq9MuU/v-deo.html
Both of those bad rails look to be using the same op amp, I would go there first.
Hello Dave would add a link to your Test clips (Grabbers0 I have never seen those before and they look handy.
Wath happen with the tek tds with a new screen repair no continuation on the proyect? try to finish that mone please
i have tektronix 5115 aka(5103) with same popping sounds. what do you think it is the problem??? my 5115 still works tho...
Just jotting down some dope here... :P
Those two 3W resistors are looking very cooked (9:20)
The one on the right of the screen looks like it has a crack in it.
Next up Dave dumpster find repair; better, faster, stronger, edition.
I think the CRT is physically broken, hence the spots on the face and HV arc.
I remember seeing those kinds of markings on the phosphor coating on CRTs when the neck of the tube were either cracked or broken, they also make a periodic popping and arcing sounds.
Sounds like arcing over at the spark gap followed by a shutdown. CRT could be broken, gone to air, or have an internal short.
video suddenly stopped in the middle of nowhere.. does YT currently have a 1st April abortion flaw ? Prof. Walter Lewins videos were also interrupted after 90sec.
What test leads are those? I totally need a set
"EB"? My initials! Just like in Journey to the Center of the Earth!