Aaaaand this is why you don't use the original commodore power supply, those things can fry your computer cause over time they fail and when they fail they usually kill your c64
Man what a SAGA! If I'm ever in a foxhole or stranded on Mars, I want you on my side! That poor Commodore 64 was practically a rebuild. Lucky you had the parts to replace it, but also kudos to you for not giving up and "working the problem" - especially when it gave you such a hard time! It just goes to show, that whilst the old Commodore 64 is quite robust and if looked after, it will last a long time, there are ones out there that have not been looked after, and for most of us who do have the grab bin of spare parts or expertise, we are better off finding ones in better condition. Great video!
Thanks man, funny enough, I was once in the infantry so I can say for certain that foxholes are no longer in my future. Too much arthritis! The bin of parts is definitely a luxury I have never enjoyed before but, sadly, they are going fast. I was really bummed that one of the 3 SID spares I found in Karl's shop died after about an hour of use.
You have far more patiance than I have, well done. Just put some silicon into the delamination gap, flexible and should stop it spreading the drier the board gets.
Guess Adrian's Digital Basement wasn't joking, some revisions of the C64 truly are cursed. Might need to use that epoxy they use to glue down traces for the stuff lifting off.
That machine works fine but I feel it is going to have reliability risks long term so, today, I pulled a good working machine I had on a display shelf down and replaced it with this one. That way it will remain with me and, if it has long term issues, I can fix them instead of someone else having to deal with it.
Superb video. I know exactly how this must have felt, and can really appreciate the work involved turning such a tough repair into a video that makes sense. Great job!
Nice video. Although, unless I missed it, I didn't see where you originally determined that the CPU was bad. There was just the bit at the end where you said you retried the original CPU and it still failed. Also, you could do worse than to pick up a TL866, if for nothing else than to test logic IC's, if you don't already have one. They're only about $35-$40 US and can save you a lot of trouble. Plus, you'll be able to program replacement EPROMs when you need them.
Hey YARC! I did not get it on camera. This thing was driving me crazy so there was a lot of off camera tinkering (Hence the future Mike stuff to explain what was going on). As it was the original CPU was used for quite a while doing tests but, since it took a couple minutes to overheat, it did not show up as bad (Or it may have been OK at that point and only failed later). I also realized in editing that I forgot to check the _NMI line but I doubt that would have helped in this case.
Great video! If the board deteriorates any more, you might consider a sixty-clone board... or you could go real crazy and put it on something like a ux64 board.
That's is an option Steve! I'm considering just using a little epoxy to reattach the ground plane on the end and prevent further delamination. I'm not certain that's a good idea so its going to stay as is for now so I don't make it any worse. This ones a problem child so I am giving it to a friend of mine so it stays close just in case it needs more attention.
YES, it freaking works! Wow that was a horrible one. U get to keep your record going:) I love how you get excited, I do the same everytime I repair one:) on the bright side.. a good vicII is fantastic as they are getting rare to find a good one. Great video. Looking forward to the next
This is 1 of those just because it could be repaired was it worth while? Only for die-hard c64 lovers this 1 especially with the board coming apart Execpt 2 keep your record intact!
Good point Greg! For me it's the fixing I enjoy most. I think the only thing that saved my record was the fact that it was making regular progress. I have an old friend that I told I would hook them up with one so it will go to him so it's close to home and I can fix any issues that pop up.
1.) The voltage thing is a myth, it probably only applies to US machines. I had only one broken C64 that may have had a PSU problem (all 8 RAMs fried) but in general, we have other PSUs, designs and problems here. E.g. some use ROE caps that short out and burn the fuse until you replace them. 2.) It is not the only or first C64 with leaked cap that I see, although that is indeed rare. It is not that one that you had but it is well known that the second rev (so called "KU board") has leaking caps installed. It eats the traces in the capsulated VIC-II section. Not sure if the KU board was sold in USA. Otherwise well done, just wish there would not always be this stupid myth of bad supplies, man that is 40 years old and it will not work until 1000 years old. Sure some will fail but no need to panic. In USA, yes, you may replace it, but in Europe it's just a big myth. Some may have 5,4V but that is without load and within tolerance, it is not 100% perfect science, often the parts have 10 or 20% tolerance. The newer the PSU is, the better, of course. Some may produce problems, but I never had any issues with the ones I used that it would be any danger to the C64. Even if the fuse blows, nothing will happen, despite you have to plug in the PSU first anyway before connecting it to the C64. I just wish people would not always talk to bad about stuff and think about everything. People panic and buy modded China-PSU that probably are 1000 times worse than the original, just because some people create this panic. TH-cam is a worldwide place, the people all over the world may watch this and they will think OH MY GOD WHAT HAPPEN and it is not really relevant to them. Probably more will get damaged to mods and panic than by the actual PSU. If it breaks, it breaks, there is no warranty in life.
Hey Stefan, I have a deal for you!!! Pay the shipping and I will ship you one of the 2 PSUs I have in my shop that put out 12v on the 5v rail. I am in the USA so they are 120v units. It is caused by one mode of failure on the type of voltage regulator used that causes it to short, rather than open, sending the unregulated voltage to the output pin. It seems to me that about 10% of the failed supplies I have seen this century have this issue with the rest just putting out no 5v. I am curious what the supply voltage used is for the voltage regulator in your PSUs. I always thought it a bit crazy that the 7405 is getting 12v on the input pin since it has to burn the excess as heat. Maybe your PSUs have a more reasonable voltage on the regulator? I would always be wary of caps installed after 1988-1990 as that is when the chemistry change was made that causes the capacitor plague. I have not worked on a KU board, in fact all my experience has been on 1982-1986ish machines. I do have some 64Cs and 128s to restore soon so that will be a new experience for me. I have seen one other cap issue on a C64 (The same cap no less) it was shorted preventing the system from starting (But no pop so not completely shorted). I do use original PSUs all the time but never without one of Ray Carlson's overvoltage protectors on it. I am happy that you don't have that issue on the other side of the pond but over here it is very real and not even unusual to see.
@@RavenWolfRetroTech yes, I believe you but you cannot generalize. Even here we have various suppliers and shapes of PSU. I even have some with screws, others are glued and filled, others (I call them China psu) have a weird Commodore logo and different looking rips, those must be late in the game. Most people probably never saw that type, I only have 2 of those. I don't know about the input voltage and as I said they are filled up with epoxy. Some people also say to be cautious with the older ones but some parts of it (like the cap I said) is even accessible and can be serviced. I never had any with 12v, some are broken or have 5.4v. As I said, everything can break but I never really had any big issues. I guess the same problem could occur on ours too, but maybe the cooling was better or it happens less often. Sure not 10%, maybe 1% or less (in my experience). But not sure how much it will handle over a longer period of time, if 5.4 is too much or in the edge, I am not sure. But I guess after the plug, the resistence and the voltage drop it may be just fine. I also have this protector thingy but idk, I like it original and not dangling around there. But I usually don't use them often but I tested everyone of them. I always use the same one when I do.
@@RavenWolfRetroTech I looked it up, both widespread models have no protection and may output 9 to 10v, according to C64 wiki. Maybe that is the input voltage on our models and it may run cooler compared to your designs, or it is better cooled. Everything can fail bit I never saw that in my whole life so for me, I will not panic about it.
I'll add to my schedule to eventually do a video looking at the various commodore power supplies. I've talked a little more in depth in older videos about the serviceable vs black brick of epoxy but i more have a much larger selection of psus. I also have a c128 psu that kills machines that I've been meaning to investigate.
That's interesting that it says 9-10v. I've also always read that but the ones i have are putting out 12v. I saved one as a sample piece and the 2nd i just discovered last week so i have not disposed of it yet. I've tried depoting bad ones but it kills my arthritis so I've just been saving the cables recently.
you probably be asking adrian digital basicment because he worked on them way more than rest of us 2nd check ram make sure not mt ram if it mt ram it trash because they failures randomly out of nowhere and some time they work for 5 sec them later it quit working you may wan5 get pcb and program it for troubleshooting in card slots which it help you narrow down troubleshooting to few thing
Aaaaand this is why you don't use the original commodore power supply, those things can fry your computer cause over time they fail and when they fail they usually kill your c64
Yep, I have one I use as an example that puts out over 12v on the 5v rail!
Always love to see the no give up attitude when working on a Commodore 64
Thanks James! I did set it aside a few times for sure!
You were patient with this one. I would have gone nuts trying to track down all those issues. Cheers!
Thanks but I actually think I did go a little nuts on this one.
Excellent video! Looks like you need another vacation:) Thanks for sharing
Lol, thanks Rudy. I am back on the Pet and thinking on what I should do next. There are so many choices!!
Man what a SAGA! If I'm ever in a foxhole or stranded on Mars, I want you on my side! That poor Commodore 64 was practically a rebuild. Lucky you had the parts to replace it, but also kudos to you for not giving up and "working the problem" - especially when it gave you such a hard time! It just goes to show, that whilst the old Commodore 64 is quite robust and if looked after, it will last a long time, there are ones out there that have not been looked after, and for most of us who do have the grab bin of spare parts or expertise, we are better off finding ones in better condition. Great video!
Thanks man, funny enough, I was once in the infantry so I can say for certain that foxholes are no longer in my future. Too much arthritis! The bin of parts is definitely a luxury I have never enjoyed before but, sadly, they are going fast. I was really bummed that one of the 3 SID spares I found in Karl's shop died after about an hour of use.
Crazy. Great job! I'm always in for some C64 videos.
More to come! You can expect a binge of your videos, my monitors have been dropping like flies (OK only 2 but thats 2 of my 3 1084s)🙄
You have far more patiance than I have, well done. Just put some silicon into the delamination gap, flexible and should stop it spreading the drier the board gets.
OMG, I can't believe it's really you! That's not a bad idea! I'll add it to my list of possible solutions! Thanks!
@@RavenWolfRetroTech It is! I can hardly believe it myself.
Jack Tramiel's younger brother fixing his C64. :D
Quite a bit of parts needed. Then again there's no telling how bad a machine is until you go through all the paces.
Nice job! Always a difficult job when you have multiple failures.
So true Frank, at least it wasn't intermittent! I hate intermittents! 😠
@@RavenWolfRetroTech Agreed! Intermittent issues are horrible. Sooo hard to troubleshoot.
Guess Adrian's Digital Basement wasn't joking, some revisions of the C64 truly are cursed. Might need to use that epoxy they use to glue down traces for the stuff lifting off.
That machine works fine but I feel it is going to have reliability risks long term so, today, I pulled a good working machine I had on a display shelf down and replaced it with this one. That way it will remain with me and, if it has long term issues, I can fix them instead of someone else having to deal with it.
Superb video. I know exactly how this must have felt, and can really appreciate the work involved turning such a tough repair into a video that makes sense. Great job!
Thank you very much!
when testing for hot chips , using a few drops off IPA can really point out the chips getting all burny :)
I have done that in the past but the finger test is an deeply ingrained habit.
I think the amount of sore fingers over the years has managed to change my diag method 😂
Nice video. Although, unless I missed it, I didn't see where you originally determined that the CPU was bad. There was just the bit at the end where you said you retried the original CPU and it still failed. Also, you could do worse than to pick up a TL866, if for nothing else than to test logic IC's, if you don't already have one. They're only about $35-$40 US and can save you a lot of trouble. Plus, you'll be able to program replacement EPROMs when you need them.
Hey YARC! I did not get it on camera. This thing was driving me crazy so there was a lot of off camera tinkering (Hence the future Mike stuff to explain what was going on). As it was the original CPU was used for quite a while doing tests but, since it took a couple minutes to overheat, it did not show up as bad (Or it may have been OK at that point and only failed later). I also realized in editing that I forgot to check the _NMI line but I doubt that would have helped in this case.
Great video! If the board deteriorates any more, you might consider a sixty-clone board... or you could go real crazy and put it on something like a ux64 board.
That's is an option Steve! I'm considering just using a little epoxy to reattach the ground plane on the end and prevent further delamination. I'm not certain that's a good idea so its going to stay as is for now so I don't make it any worse. This ones a problem child so I am giving it to a friend of mine so it stays close just in case it needs more attention.
YES, it freaking works! Wow that was a horrible one. U get to keep your record going:) I love how you get excited, I do the same everytime I repair one:) on the bright side.. a good vicII is fantastic as they are getting rare to find a good one. Great video. Looking forward to the next
Thanks Donald! I am hoping I just got the worst machine from the Stone collection over with. Sadly the statistical probability is not good!
Replace the 5 V regulator and put a suppressor diode after it.
Well done commander (Excellent)!
For some reason that comment made me think of Wing Commander. Thanks Alen!
This is 1 of those just because it could be repaired was it worth while? Only for die-hard c64 lovers this 1 especially with the board coming apart
Execpt 2 keep your record intact!
Good point Greg! For me it's the fixing I enjoy most. I think the only thing that saved my record was the fact that it was making regular progress. I have an old friend that I told I would hook them up with one so it will go to him so it's close to home and I can fix any issues that pop up.
1.) The voltage thing is a myth, it probably only applies to US machines. I had only one broken C64 that may have had a PSU problem (all 8 RAMs fried) but in general, we have other PSUs, designs and problems here. E.g. some use ROE caps that short out and burn the fuse until you replace them.
2.) It is not the only or first C64 with leaked cap that I see, although that is indeed rare. It is not that one that you had but it is well known that the second rev (so called "KU board") has leaking caps installed. It eats the traces in the capsulated VIC-II section. Not sure if the KU board was sold in USA.
Otherwise well done, just wish there would not always be this stupid myth of bad supplies, man that is 40 years old and it will not work until 1000 years old. Sure some will fail but no need to panic. In USA, yes, you may replace it, but in Europe it's just a big myth. Some may have 5,4V but that is without load and within tolerance, it is not 100% perfect science, often the parts have 10 or 20% tolerance. The newer the PSU is, the better, of course. Some may produce problems, but I never had any issues with the ones I used that it would be any danger to the C64. Even if the fuse blows, nothing will happen, despite you have to plug in the PSU first anyway before connecting it to the C64.
I just wish people would not always talk to bad about stuff and think about everything. People panic and buy modded China-PSU that probably are 1000 times worse than the original, just because some people create this panic. TH-cam is a worldwide place, the people all over the world may watch this and they will think OH MY GOD WHAT HAPPEN and it is not really relevant to them. Probably more will get damaged to mods and panic than by the actual PSU. If it breaks, it breaks, there is no warranty in life.
Hey Stefan, I have a deal for you!!! Pay the shipping and I will ship you one of the 2 PSUs I have in my shop that put out 12v on the 5v rail. I am in the USA so they are 120v units. It is caused by one mode of failure on the type of voltage regulator used that causes it to short, rather than open, sending the unregulated voltage to the output pin. It seems to me that about 10% of the failed supplies I have seen this century have this issue with the rest just putting out no 5v. I am curious what the supply voltage used is for the voltage regulator in your PSUs. I always thought it a bit crazy that the 7405 is getting 12v on the input pin since it has to burn the excess as heat. Maybe your PSUs have a more reasonable voltage on the regulator?
I would always be wary of caps installed after 1988-1990 as that is when the chemistry change was made that causes the capacitor plague. I have not worked on a KU board, in fact all my experience has been on 1982-1986ish machines. I do have some 64Cs and 128s to restore soon so that will be a new experience for me. I have seen one other cap issue on a C64 (The same cap no less) it was shorted preventing the system from starting (But no pop so not completely shorted).
I do use original PSUs all the time but never without one of Ray Carlson's overvoltage protectors on it. I am happy that you don't have that issue on the other side of the pond but over here it is very real and not even unusual to see.
@@RavenWolfRetroTech yes, I believe you but you cannot generalize. Even here we have various suppliers and shapes of PSU. I even have some with screws, others are glued and filled, others (I call them China psu) have a weird Commodore logo and different looking rips, those must be late in the game. Most people probably never saw that type, I only have 2 of those.
I don't know about the input voltage and as I said they are filled up with epoxy. Some people also say to be cautious with the older ones but some parts of it (like the cap I said) is even accessible and can be serviced.
I never had any with 12v, some are broken or have 5.4v. As I said, everything can break but I never really had any big issues.
I guess the same problem could occur on ours too, but maybe the cooling was better or it happens less often. Sure not 10%, maybe 1% or less (in my experience).
But not sure how much it will handle over a longer period of time, if 5.4 is too much or in the edge, I am not sure. But I guess after the plug, the resistence and the voltage drop it may be just fine.
I also have this protector thingy but idk, I like it original and not dangling around there. But I usually don't use them often but I tested everyone of them. I always use the same one when I do.
@@RavenWolfRetroTech I looked it up, both widespread models have no protection and may output 9 to 10v, according to C64 wiki. Maybe that is the input voltage on our models and it may run cooler compared to your designs, or it is better cooled. Everything can fail bit I never saw that in my whole life so for me, I will not panic about it.
I'll add to my schedule to eventually do a video looking at the various commodore power supplies. I've talked a little more in depth in older videos about the serviceable vs black brick of epoxy but i more have a much larger selection of psus. I also have a c128 psu that kills machines that I've been meaning to investigate.
That's interesting that it says 9-10v. I've also always read that but the ones i have are putting out 12v. I saved one as a sample piece and the 2nd i just discovered last week so i have not disposed of it yet. I've tried depoting bad ones but it kills my arthritis so I've just been saving the cables recently.
you probably be asking adrian digital basicment because he worked on them way more than rest of us
2nd check ram make sure not mt ram if it mt ram it trash because they failures randomly out of nowhere and some time they work for 5 sec them later it quit working
you may wan5 get pcb and program it for troubleshooting in card slots which it help you narrow down troubleshooting to few thing
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