@Michael O Callaghan that hows ya learn. or at least how i did. Right now im working on a NES console that someone lifted 80% of the traces on cuz they didnt know what they were doing. I told them i could probably fix, but now they know not how to do it lol
My first 12” black and white tv had a white dot minutes after turning off... My parents knew this so when I heard steps on the stairs I was already to late 😂
@@Wewewea Turning brightness to 0/zero is the correct way to say it. But saying "turning brightness too 0/zero" makes no sense. Google, Bing and Duck Duck Go agree with me. Just like saying "I'm going to work/going to correct you/going to turn my volume to 0/zero" am I wrong?
Excuse my language, but holy fucking shit. My dad has a older model PET 2001 where the bright spot has bothered him for the last 15-20 years. When mentioning it, its all he ever talks about and how he could never get it fixed. I'm going to "borrow" his PET '01 and apply these fixes as a Christmas present. Thank you so, so much Adrian! Greetings from Norway!
For a better and more in depth technical explanations of the cause of the spot and the fix, please watch Frank's (IZ8DWF) video on the subject: ua-cam.com/video/WULJxrQkQeg/v-deo.html Update: Chuck has applied the fix to his monitor as well, see his results here: ua-cam.com/video/iMSQTCdC-jg/v-deo.html
The thing is, while he's trouble shooting, he's not an engineer, he's learning along the way. We are picking up, what he's putting down. He tries, isn't afraid, and this is working out well for him and the rest of us.
Thrilling as a sports match! I was actually shouting out loud "Ohh nooo!" when the capacitor didn't fully fix it. Great to see you getting to the bottom of this. Well done!
Funny enough, the entire time of it not being fixed (at this stage I mean) I was screaming in my head - get to a cap dude! I was for sure that once he did, it was a done deal. hahaha
I don’t know how but Adrian suddenly got me interested in a pesky spot in a ‘70s machine that I never really cared for. Love you Adrian for making such engaging content and providing so many hours of great entertainment! Keep up the great content!
Just did the mod of changing R2 2k2 to 470R in series with 8.2 zener on a 3032 PET. The rest of the components are already at the correct values. The annoying spot has gone. Thank you Adrian and Frank!
Great work Adrian! I can imagine how much work it was to fix this. Sometimes things are looking so simple in the videos, like it took 10 Minutes to fix it, but sometimes you have to try it again and again and it actually takes months. I know it too good :) Thumbs up!
This is very interesting - I have a 2001-8 with chicklet keyboard and tape which I've had since 1979 (well, my dad bought it but I commandeered it!) and needs refurbing someday. I'll keep a note of this video for when its time comes (which hopefully will be 2021!) I remember back in '85 when I last used it I would get a faint spot a few seconds after turning it off (only really visible in a darkened room) that lasted for a minute or two. Since its been unused for ~35 years its going to need a complete refurb and I will put in the mod and check the 33v Zener! Great channel Adrian, I found you through one of your earlier PET videos. Theres not a huge amount on UA-cam with these PETs, most of the attention these days is on the later more glamourous machines, but I learnt to code on my (*cough* Dads) PET and the skills it taught me have been good to me in my working life. On another note, are you trying to collect ALL the SIM RAM in the world? :D Say Hi to Rammy for me!
Fascinating. I wasn't sure that you were going to find the solution to this problem. But then again, who am I kidding -- great job -- and process duly noted. I have two PETs yet to be tended to and I will be sure to remember this great solution. 👍
Hi @Adrian's Digital Basement, another great video, I love problem solving videos, it is nice to know I am not the only one that has to spend ages fixing issues like this, looking forward to the next one. 👍
Hi Adrian, thanks a lot for all this amazing content you upload. I’m 20 years old, I’ve never seen, used or even heard of any of the devices you show in your videos but somehow I can’t get my eyes away from the screen from the moment they begin to the moment they end! It never happened to me before, I guess that’s what happens when you find a genuinely interesting and talented youtuber.
I own both a chiclet 2001 (1st revision analog board) and a 2001-N (2nd revision analog board). After applying the spot fixes according to your video, the 2001-N has been spot-free for a year now. I can't draw a conclusion on the chiclet 2001 yet as I only got it properly running a few days ago, but so far the fix seems to do its job very well.
It's funny that as this came up in my feed I am working on editing my video about fixing an IBM 5154. So, I have something very relevant to watch while I wait for rendering to happen. Thanks!
Congratulations on this particular video. It is clearly perceived the large amount of work behind. Researching, exchanging impressions with colleagues or mounting / dismounting the monitors with which you have done the tests.
That was great, one of the best troubleshooting vids I've seen. I'm old enough to have, in a previous life, to have been CRT TV repairman. This brought back memories.
I love this troubleshooting adventure and great investigation and explanation. Personally I'm lazy and would have just lived with it as I've never seen an original PET with any burn-in from 'the spot', and I actually find it kind of charming, like some ancient TVs that did this when I was a kid. I have a next-gen PET, a 2001 (3032) "Professional Computer" and it does not suffer from the spot though.
4.4K likes, 43 dislikes, yep I think that sums up how enjoyable this series is. I'm very much an electronics newbie though I used to build computers to pay my way through Uni in the 90s. This would be beyond me but I've learnt a lot. Thank you.
I love watching the methodical way you troubleshoot these problems, Adrian! It's great to share a part of the satisfaction once these tricky bugs are sqaushed. Great work as always!
Never had so much fun watching a spot .We need this to a be yearly event , spot watching 2021.I'm kidding of course , great vid . I hope you and your viewers have a great year in 2021
Wish I could give you 10,000 likes! Congratulations. What a quest :D Nice job to all involved but Adrian your persistence is what solved this. I find this type of content so satisfying it's like defeating a boss at the end of a 200hr game.
23:39 I had a Mitsubishi TV from the 1973 with that instant-on feature. It did run the heater at reduced voltage so didn't cause any significant tube life issue. The TV got scrapped a few years ago, just because no-one wanted it, but it still worked! 33:12 I've never thought to keep a dead parts bin. Mine would be very full indeed by now, mostly of smelly electrolytic capacitors.
That model with the chicklet keyboard and built-in cassette drive was where I first saw the "Hunt The Wumpus" game. I recorded the tunnel connections onto paper and wrote my own version of the game using just that information along with the knowledge that there were exactly two pits and exactly two caves with bats. 😄 Anyway, grats on fixing the problem.
It took me until 33:50 when you mentioned 47 microfarad for C22 to actually realize that it was 47. Earlier in the video when you applied the actual fix, I was thinking 4.7 the whole time. I made a comment trying to correct what I saw and heard but deleted it as you are correct in your video throughout. I am glad for you and enjoy!
My parents used to admonish me for watching too much Tv as a child (40+ years ago)......."You would watch the dot" they would say....now i know what they meant !!
Nice to see you figured it out in the end! First thing I noticed that was different was the flyback transformer design, as you mentioned, but I just guessed that perhaps Commodore had a different manufacturer for the later ones.
Im always in awe of the efforts and time you devote for such a noble goal of maintening those pieces of history, kudos sir keep them coming, always very enjoyable. ( and kudos to the wifey too for enabling you for our enjoyement xD )
Adrian, I would strongly suggest replacing ALL the electrolytics. As you noted, the ESR of those caps are pretty bad. They are after all 50 years old. Heat and age are not doing them any favors.
I wonder if that zener is really bad. It may not be. As you said, all semiconductors tend to leak when hot. Just because that diode was leaky when hot, does not mean it has failed. Just changing the dropping resistor may have fixed the issue. Pro tip: When trying fixes, try to change only one variable at a time. If you change two parts, and the problem is fixed, which part was actually bad? Potentially none. The resistor was obviously fine, the zener may have had issues, but now we'll never know. I would have changed the resistor first (too small a dropping resistor is a n00b mistake, commodore), and tested. But swapping the zener out certainly did no harm, so there is that.
ADRIAN!!!! Im in So California. its cold and dry today....I reached over to my laptop to move the screen..an ZAAAPPP!! (static discharge) at 22:03 I thought I touched the flyback on your video!!!! I can't stop laughing....!!
The "dot" is residual charge left behind somewhere and released (discharged) into the monitor, the trick would be to find the part of the circuit that is responsible for fast discharge after the monitor has been turned off. The voltage affects the X/Y positioning of the beam, so... technically that could be a thing too.
Hahaha, I love it... using a desoldering station till solder. The irony and upright frankness about doing so. That settles it, Im sending a Christmas present.
Hello Adrian from Nottingham UK. Just want to show my total and absolute appreciation for the effort you put into your videos my friend. My GOTO to escape from the nonsensical human malware that we're all suffering through ATM. Please Please keep up the astronomical effort you are putting into these fantastic recordings. It is truly the very best channel available on UA-cam right now. Both you and Mark fixes stuff are keeping me sane lmao 👾🕹️😂. Love what you are doing Mr. Black.. Hey!!! You should be a character on a Captain Scarlet hehe he 😂
Nice work Adrian, you've been very committed to fixing this one little problem and I'm glad you got it sorted. (How did this video get dislikes?! Seriously, this is dedication!)
You were very brave to turn it off with the heater voltage still on. I know the cathode has about 5 to 10 seconds of thermal retention. Quite a lot of spot supresion circuits rely on the fact the cathode will be cool enough after this time, oe the EHT has bled away. I noticed the spot was a lot brighter when you powered the heater from your bench PSU.
15:27 - the differences are down to yours catering to the home/personal market the loan one catering to the professional market, the green screen was considered to reduce eye fatigue, the keyboard also was a better design (IIRC they where hall effect switches rather than the traditional mechanical ones)
unrelated, but one of my family's last TVs lasted about 12 years, until we replaced it with a flat panel we got from a family member, we replaced it because it was taking upwards of 2 minutes to warm up, when usually it only takes about 10-30 seconds. it was a zenith i believe. I think that's very good life for being turned on for at least 14 hours a day for 12 years, and knowing my dad, we probably got it used so add that on top.
Hey Adrian, I haven't seen anyone commenting this nor heard it in your video or description (unless I missed it), so since you seemed not really ticked off at the higher value, here is a quick tip with capacitors, if they read above their rated µF value, especially that much higher, you can be sure the capacitor is bad and needs replacement, only way it can be an overachiever is by leaking electrically, aka, it's getting shorted, taking longer to discharge, appearing to have a greater capacity than it should. Hopefully this little tip can help you diagnose things a little faster and with more confidence! This might save you from a magic smoke show some day hah. Cheers, -Noma
Hi Adrian, I've got a CBM 2001-8. After seeing your videos about this issue, I checked out if the monitor of my model had the same problem and I have to say it shows no lighting spot during the power off phase, absolutely no issue. So I decided to further investigate and I opened the metal plate which cover the back of the monitor. To my surprise the motherboard is totally different from the two I saw in your videos, mine also has the silkscreen for the components. Unfortunately the numbers of the components don't match with your schematics, so I can't figure out what are the changes Commodore made to this board in regards to the one you have. Also the placement of the components is different. I bought this computer sometime ago from the Harden S.p.A., which was the Commodore computer importer company in the late '70 - early '80, when in Italy there was no Commodore italian subsidiary yet.
Adrian has this 'never say die' attitude, that you gotta admire
I love it. It keeps me going on my projects that I have come to dead ends on of my own.
Agreed. Something I used to have, but it has waned somewhat in the past few years ... sigh!
If he had been a doctor he'd go the way of Dr Frankenstein for sure.
@Michael O Callaghan I tend to buy things from either local flea markets and thriftstores, or even ebay that are broken, just to try to fix them. lol
@Michael O Callaghan that hows ya learn. or at least how i did. Right now im working on a NES console that someone lifted 80% of the traces on cuz they didnt know what they were doing. I told them i could probably fix, but now they know not how to do it lol
My first 12” black and white tv had a white dot minutes after turning off...
My parents knew this so when I heard steps on the stairs I was already to late 😂
Hahaha foiled by a bad design!!
Too*
@@Wewewea No, they were correct by saying "to" .. By being a grammar nazi, you made yourself look like a muppet!
@@EzeePosseTV You’re obviously wrong. ‘To’ is a preposition and ‘too’ is an adverb.
@@Wewewea Turning brightness to 0/zero is the correct way to say it. But saying "turning brightness too 0/zero" makes no sense. Google, Bing and Duck Duck Go agree with me. Just like saying "I'm going to work/going to correct you/going to turn my volume to 0/zero" am I wrong?
Excuse my language, but holy fucking shit. My dad has a older model PET 2001 where the bright spot has bothered him for the last 15-20 years. When mentioning it, its all he ever talks about and how he could never get it fixed. I'm going to "borrow" his PET '01 and apply these fixes as a Christmas present. Thank you so, so much Adrian! Greetings from Norway!
Adrian's gonna have that thing running at 800x600, full color, with a GUI driven Commodore BASIC interface by the time this is all over! :)
Then it will gain sentience and kill us all! No, Adrian no!
Replace the mainboard with a Raspberry Pi and the CRT with a 4K LCD panel.
@@Okurka. That would be blasphemous to such a beautiful and classic computer to put that crap in it.
yeah but i bet the spot will stil show up :_:
Adrian is gay? Awesome! No have many gays in old eletronic
"Out, damned spot!"
--William Shakespeare...
at the drycleaner?
Vamoose ya little varmint !
I was going to go there, but you beat me to it.
"Begone, thou foul, malingering spot!"
@@knghtbrd Ditto. Like minds think alike! That line is also from Macbeth, FYI.
For a better and more in depth technical explanations of the cause of the spot and the fix, please watch Frank's (IZ8DWF) video on the subject:
ua-cam.com/video/WULJxrQkQeg/v-deo.html
Update: Chuck has applied the fix to his monitor as well, see his results here: ua-cam.com/video/iMSQTCdC-jg/v-deo.html
🎃
You are the retro-world's best troubleshooter.
The thing is, while he's trouble shooting, he's not an engineer, he's learning along the way. We are picking up, what he's putting down. He tries, isn't afraid, and this is working out well for him and the rest of us.
Adrian your perseverance is so high that you really inspire other people to be like you. Good Job!
Thrilling as a sports match! I was actually shouting out loud "Ohh nooo!" when the capacitor didn't fully fix it. Great to see you getting to the bottom of this. Well done!
Funny enough, the entire time of it not being fixed (at this stage I mean) I was screaming in my head - get to a cap dude! I was for sure that once he did, it was a done deal. hahaha
Man vs Dot! - new exciting series!
It was now a matter of principle, to eliminate that spot!!
I don’t know how but Adrian suddenly got me interested in a pesky spot in a ‘70s machine that I never really cared for. Love you Adrian for making such engaging content and providing so many hours of great entertainment! Keep up the great content!
Great mini-series, I am now emotionally invested into the state of Chuck's PET, hope the fix works for him as well!
Just did the mod of changing R2 2k2 to 470R in series with 8.2 zener on a 3032 PET. The rest of the components are already at the correct values. The annoying spot has gone. Thank you Adrian and Frank!
What a rollercoaster. Every time I was holding my breath, waiting to see if the dot appears.
Adrian, at times you are really 'hardcore'. That spot must have REALLY been buggin' you. Good work!
Great work Adrian! I can imagine how much work it was to fix this. Sometimes things are looking so simple in the videos, like it took 10 Minutes to fix it, but sometimes you have to try it again and again and it actually takes months. I know it too good :) Thumbs up!
This is very interesting - I have a 2001-8 with chicklet keyboard and tape which I've had since 1979 (well, my dad bought it but I commandeered it!) and needs refurbing someday. I'll keep a note of this video for when its time comes (which hopefully will be 2021!)
I remember back in '85 when I last used it I would get a faint spot a few seconds after turning it off (only really visible in a darkened room) that lasted for a minute or two. Since its been unused for ~35 years its going to need a complete refurb and I will put in the mod and check the 33v Zener!
Great channel Adrian, I found you through one of your earlier PET videos. Theres not a huge amount on UA-cam with these PETs, most of the attention these days is on the later more glamourous machines, but I learnt to code on my (*cough* Dads) PET and the skills it taught me have been good to me in my working life.
On another note, are you trying to collect ALL the SIM RAM in the world? :D Say Hi to Rammy for me!
Fascinating. I wasn't sure that you were going to find the solution to this problem. But then again, who am I kidding -- great job -- and process duly noted. I have two PETs yet to be tended to and I will be sure to remember this great solution. 👍
Hi @Adrian's Digital Basement, another great video, I love problem solving videos, it is nice to know I am not the only one that has to spend ages fixing issues like this, looking forward to the next one. 👍
The drama that comes from the waiting for the dot to appear is fantastic. Thanks for another great video.
No joke, one of the most rivetting and thrilling set of videos I've ever watched on UA-cam. A retro electronics drama like no other!
Adrian, I don't own a Pet but Your commitment to solve the problem is simply remarkable
what an amazing example of archaeology!! tracing previous repairs from another era, beautiful stuff
This really gives a new meaning to a Spotfix on your computer.
Hi Adrian, thanks a lot for all this amazing content you upload. I’m 20 years old, I’ve never seen, used or even heard of any of the devices you show in your videos but somehow I can’t get my eyes away from the screen from the moment they begin to the moment they end! It never happened to me before, I guess that’s what happens when you find a genuinely interesting and talented youtuber.
This man is a professional, despite not having degrees in electronics.
I own both a chiclet 2001 (1st revision analog board) and a 2001-N (2nd revision analog board).
After applying the spot fixes according to your video, the 2001-N has been spot-free for a year now. I can't draw a conclusion on the chiclet 2001 yet as I only got it properly running a few days ago, but so far the fix seems to do its job very well.
I have never in my life felt so much suspense over a dot. 😂🤣😂 Thanks for the great video!
It's funny that as this came up in my feed I am working on editing my video about fixing an IBM 5154. So, I have something very relevant to watch while I wait for rendering to happen. Thanks!
That is the best feeling ever, working on something and trying diffrent things multiple times, and FINALLY fixing it. 😃😃
I've never been so on the edge of my seat while awaiting the arrival of a spot!
Except maybe that time involving a pregnancy test?
Congratulations on this particular video. It is clearly perceived the large amount of work behind. Researching, exchanging impressions with colleagues or mounting / dismounting the monitors with which you have done the tests.
Glad you persisted with it.
After following the first part I was disappointed when I saw the Pet reassembled initially but not fully fixed.
Fair do's Richard Dreyfuss. Your tenacity earns you a subscriber.
That was great, one of the best troubleshooting vids I've seen. I'm old enough to have, in a previous life, to have been CRT TV repairman. This brought back memories.
I love this troubleshooting adventure and great investigation and explanation. Personally I'm lazy and would have just lived with it as I've never seen an original PET with any burn-in from 'the spot', and I actually find it kind of charming, like some ancient TVs that did this when I was a kid. I have a next-gen PET, a 2001 (3032) "Professional Computer" and it does not suffer from the spot though.
This video was extreme satisfying. I’m glad you never gave up on fixing it
Well done Adrian, nice to know what the actual problem was, cheers!
The 'R2 -) On all revisions, replace resistor R2 with a 8.2v Zener and 470 ohm resistor in series' fixed my 2001...thank you
4.4K likes, 43 dislikes, yep I think that sums up how enjoyable this series is. I'm very much an electronics newbie though I used to build computers to pay my way through Uni in the 90s. This would be beyond me but I've learnt a lot. Thank you.
I love watching the methodical way you troubleshoot these problems, Adrian! It's great to share a part of the satisfaction once these tricky bugs are sqaushed. Great work as always!
Never had so much fun watching a spot .We need this to a be yearly event , spot watching 2021.I'm kidding of course , great vid . I hope you and your viewers have a great year in 2021
Wish I could give you 10,000 likes! Congratulations. What a quest :D Nice job to all involved but Adrian your persistence is what solved this. I find this type of content so satisfying it's like defeating a boss at the end of a 200hr game.
This was a thriller with a lot of plot twists. Very interesting, thank you!
The diode wasn't zen enough, I need a zener diode ...
Ok, I'll get out ...
One that's not so prone to breakdowns?
Puns are art by my book and have to be appreciated. That one was quite good!
😂😂😂 I assume you’ll let yourself out...
no no, don't leave. I'll be here all night. Please, stick around. I can't resist a good pun.
@@Kylefassbinderful
What happened to the overheated magnet?
He gave up the Gauss.
Glad you finally got this fixed and what a way to end 2020. Never before in UA-cam history has staring at a black screen been so exciting.
Perseverance pays off in the end. Great Job!
23:39 I had a Mitsubishi TV from the 1973 with that instant-on feature. It did run the heater at reduced voltage so didn't cause any significant tube life issue. The TV got scrapped a few years ago, just because no-one wanted it, but it still worked!
33:12 I've never thought to keep a dead parts bin. Mine would be very full indeed by now, mostly of smelly electrolytic capacitors.
That model with the chicklet keyboard and built-in cassette drive was where I first saw the "Hunt The Wumpus" game. I recorded the tunnel connections onto paper and wrote my own version of the game using just that information along with the knowledge that there were exactly two pits and exactly two caves with bats. 😄
Anyway, grats on fixing the problem.
You have the dedication of a scientist. Very well done!
Great video!! Really tricky failure and very entertaining root cause analysis. 👍🏻. Greetings from CPUGALAXY 🇦🇹
It took me until 33:50 when you mentioned 47 microfarad for C22 to actually realize that it was 47. Earlier in the video when you applied the actual fix, I was thinking 4.7 the whole time. I made a comment trying to correct what I saw and heard but deleted it as you are correct in your video throughout. I am glad for you and enjoy!
More ups and downs than a thriller movie!! Nice work.
This was a GREAT video. It really shows how such a seemingly small issue can eat up so much time.
Yay, Adrian! I am glad you found this issue with that light spot. You are like the Sherlock Holmes of circuit troubleshooting!
My parents used to admonish me for watching too much Tv as a child (40+ years ago)......."You would watch the dot" they would say....now i know what they meant !!
Well done... "Out damned Spot" I love this type challenging troubleshooting to resolve a complex problem
Nice congrats that you finally fixed it! Nice job documenting everything hopefully this helps other pet owners with this annoying problem
What an ordeal to sort it out. Great work. Next how about a Mod to convert the display output from the CRT to a more modern LCD display.
Adrian I received the parts today and got them installed. I did all the mods as well as replacing all the older capacitors. Guess what no more dot!!
Glad you got yours figured out, crt are a nightmare 70% science and 30% art.
Such patience. Time to dig out my PET and get it fixed too.
Nice to see you figured it out in the end! First thing I noticed that was different was the flyback transformer design, as you mentioned, but I just guessed that perhaps Commodore had a different manufacturer for the later ones.
Realy fantastic your perseverance to fixing that problem.
Congratulations!!!
Excellent work! My 2001 has a very nasty spot so I should investigate this.
Really enjoyed this. Glad you stuck with it and persevered.
I love when you find a solution for a problem! Congrats!
The flyback transformer was the first thing I noticed being different.
Im always in awe of the efforts and time you devote for such a noble goal of maintening those pieces of history, kudos sir keep them coming, always very enjoyable. ( and kudos to the wifey too for enabling you for our enjoyement xD )
Adrian, I would strongly suggest replacing ALL the electrolytics. As you noted, the ESR of those caps are pretty bad. They are after all 50 years old. Heat and age are not doing them any favors.
“Adrian’s ANALOGUE basement”!!? Great video, as always.
Great content. You do not give up fixing a problem until it is solved. I like that. Keep it up!!
I wonder if that zener is really bad. It may not be. As you said, all semiconductors tend to leak when hot. Just because that diode was leaky when hot, does not mean it has failed. Just changing the dropping resistor may have fixed the issue.
Pro tip: When trying fixes, try to change only one variable at a time. If you change two parts, and the problem is fixed, which part was actually bad? Potentially none. The resistor was obviously fine, the zener may have had issues, but now we'll never know. I would have changed the resistor first (too small a dropping resistor is a n00b mistake, commodore), and tested.
But swapping the zener out certainly did no harm, so there is that.
ADRIAN!!!! Im in So California. its cold and dry today....I reached over to my laptop to move the screen..an ZAAAPPP!! (static discharge) at 22:03 I thought I touched the flyback on your video!!!! I can't stop laughing....!!
The "dot" is residual charge left behind somewhere and released (discharged) into the monitor, the trick would be to find the part of the circuit that is responsible for fast discharge after the monitor has been turned off. The voltage affects the X/Y positioning of the beam, so... technically that could be a thing too.
Your Pet with the chicklet keyboard is sure a fine looking machine, gosh it looks new.
Your determination is admirable as all hell. Bravo good sir.
What a roller coaster ride that was 😅 Well done sticking with it all this time.
Hahaha, I love it... using a desoldering station till solder. The irony and upright frankness about doing so. That settles it, Im sending a Christmas present.
Hello Adrian from Nottingham UK.
Just want to show my total and absolute appreciation for the effort you put into your videos my friend.
My GOTO to escape from the nonsensical human malware that we're all suffering through ATM.
Please Please keep up the astronomical effort you are putting into these fantastic recordings.
It is truly the very best channel available on UA-cam right now.
Both you and Mark fixes stuff are keeping me sane lmao 👾🕹️😂.
Love what you are doing Mr. Black..
Hey!!!
You should be a character on a Captain Scarlet hehe he 😂
Nice work Adrian, you've been very committed to fixing this one little problem and I'm glad you got it sorted. (How did this video get dislikes?! Seriously, this is dedication!)
You were very brave to turn it off with the heater voltage still on. I know the cathode has about 5 to 10 seconds of thermal retention. Quite a lot of spot supresion circuits rely on the fact the cathode will be cool enough after this time, oe the EHT has bled away.
I noticed the spot was a lot brighter when you powered the heater from your bench PSU.
15:27 - the differences are down to yours catering to the home/personal market the loan one catering to the professional market, the green screen was considered to reduce eye fatigue, the keyboard also was a better design (IIRC they where hall effect switches rather than the traditional mechanical ones)
Really excellent video Adrian, fascinating stuff and pretty awesome to see a working fix in the end!
That's awesome. Nice work.
Your t-shirt mic looks like something out of that godawful Rutger Hauer flick, "Wedlock" :)
You just made me watch spots for forty minutes, congratulations
unrelated, but one of my family's last TVs lasted about 12 years, until we replaced it with a flat panel we got from a family member, we replaced it because it was taking upwards of 2 minutes to warm up, when usually it only takes about 10-30 seconds. it was a zenith i believe. I think that's very good life for being turned on for at least 14 hours a day for 12 years, and knowing my dad, we probably got it used so add that on top.
That was quite a bug hunt! I'm glad you managed to fix that spot :D
I think the spot was the PET's soul and you killed it :(
:D
Job's Garage well that got depressing fast
Great video Adrian, well done for finally fixing the monitor issue. Keep up the great work!
I said "One hour latairrr" about 15 seconds before you added that in.
Don’t be so sure about the spark gaps... unless they’re sealed, dirt and corrosion could get in the space between the gap, causing leakage.
A big piece of cheese cake, a big cup of coffee and Adrian's Digital Basement - I like my birthday now! :)
An awesome effort Adrian... well done.
a spotless video.... oh wait.. lol. I can imagine the feeling of fixing an annoying problem. Well done Adrian.
Hey Adrian,
I haven't seen anyone commenting this nor heard it in your video or description (unless I missed it), so since you seemed not really ticked off at the higher value, here is a quick tip with capacitors, if they read above their rated µF value, especially that much higher, you can be sure the capacitor is bad and needs replacement, only way it can be an overachiever is by leaking electrically, aka, it's getting shorted, taking longer to discharge, appearing to have a greater capacity than it should.
Hopefully this little tip can help you diagnose things a little faster and with more confidence!
This might save you from a magic smoke show some day hah.
Cheers,
-Noma
Hi Adrian, I've got a CBM 2001-8. After seeing your videos about this issue, I checked out if the monitor of my model had the same problem and I have to say it shows no lighting spot during the power off phase, absolutely no issue. So I decided to further investigate and I opened the metal plate which cover the back of the monitor. To my surprise the motherboard is totally different from the two I saw in your videos, mine also has the silkscreen for the components. Unfortunately the numbers of the components don't match with your schematics, so I can't figure out what are the changes Commodore made to this board in regards to the one you have. Also the placement of the components is different. I bought this computer sometime ago from the Harden S.p.A., which was the Commodore computer importer company in the late '70 - early '80, when in Italy there was no Commodore italian subsidiary yet.
Wonderful diagnosis and great information.
Sweet victory! Congratulations sir.