Thank you for talking about magnet wire. Also known as magwire, this wire is great for repairs or adding traces as part of a mod. Magwire is very popular across multiple industries that repair circuit cards because of the small form factor and reliability. Excellent troubleshooting video.
First time watcher, I saw the title and immediately thought, "this has got to be a later breadbin, 84 or 85, the MOS chips on those were spotty as heck." Then when you opened it up and I saw all of the bodge work and newer chips installed post-factory production, I knew we were in for a ride. Like a Fuck-Me Sundae on top of a Shit Sandwich.
I prefer to use wire wrap for bodges. I'm glad to see someone else who knows that machine pin sockets are the worst. Double wipe sockets are so much better.
I also feel your pain. I am currently working on the same board that came with a few botched wires and some rework done. Grr. I had to walk away. Lol I love your dedication. Looking forward to part 2.
Yeah, I've walked away from a few myself because in my case, and probably the same for a lot of us, we usually have a few nice boards and not enough parts (of the expensive to replace chips like vic or sid) to get them all complete even if we fixed them. The challenge is nice, but sometimes you have to manage your time towards projects with the highest personal reward.
I find when using magnet wire that it's much easier to tin the ends of the wire with the iron before soldering it to the PCB or component. It takes quite while to melt the insulation and you risk damage to the pads while that happens, it's also quite easy to flow solder over the insulation and not realise it's not melted. Your continuity test would have picked that up though. The insulation melts quickest if you start with the solder on the cut end, it gets more heat into the copper quicker.
That board is a mess. Yeesh! Not sure I'd have the same patience to rebodge that whole board (unless it was for a friend), but I certainly wouldn't trust the original bodge wires with such a shoddy job it seems was done to this board.
I admire your persistence. I would not even started to try to fix this... your engineering hours are more costly than what the machine worth. Of curse as an entertainment it is interesting but still... The ending is the BEST when sitting there with a beer. I think you definitely deserved that :-) Looking forward for part 2 to know what else did you find.
Yep, it certainly doesn't make sense from a financial standpoint and I considered using it as a parts board, but I can't resist a challenge. I did underestimate just how much time it took to get those ICs off, it's much harder when the pads are already missing, and cleanup wasn't any easier. Beers were a must
It did remind me of that ZX Spectrum you repaired a couple of months ago, especially as a lot of the solder mask on the traces running in between the pins is gone
Definitely be back for part 2, you may just have helped me with a c64 i'm trying to repair, dead test is giving me 6 flashes I swapped out the RAM at u10 and u11 but I'm still getting 6 flashes. U11 was replaced because it had been previously replaced. 👍
Depends on the board revision. Early ones would be U22, but the later ones with only 2 RAM ICs will be U10 (and the other is U11). I'm guessing it's a later one as Tony mentioned replacing U10 and U11. But either way the dead test is indicating an issue with data bit 2, so could be something else corrupting that bit
Ah, in that case you could also try and piggyback another 4164 on top of U22 and see if you get any result. Just make sure you have good contact between the legs on both chips. I usually push down on top of the one... on top to make sure all legs are touching the one below
The RAM waveforms 14:13 were from pins 3, 4 and 5 (I think). So we're looking at writes to the RAM on pin 3 which happens sporadically, RAS on pin 4 which happens more often at a consistant rate (CAS on pin 15 should look similar), and an address line on pin 5. All of the signals looked pretty standard for a 4164 D-RAM - going between ground and +5V with nothing stuck high, low or in the middle. As DRAM needs to be constantly refreshed, you generally should always see activity if the system is running. Pin 5 of U25 14:35 (don't remeber exactly what that IC was but it's a 74LS series logic), was sitting around 2V. Like the RAM it should have 0V or +5V, but never 2V. I initially suspected it was a conflict between something trying to drive it high +5V or low 0V, but it turns out it wasn't connected at all, and the reading around 2V was just because it wasn't connected - floating. The faulty MOS logic 17:52 seemed to work fine sometimes (activity between 0V and +5V) but every so often certain gates would be stuck at 0V. In theory it should have looked the same every time, as I didn't change anything else during power cycles.
Good luck with it. I thought this would be another simple fix like a bad PLA. But I turned the camera on just in case it was something different, think I got more than I bargained for
@@TheRetroChannel My God. It's brand new. Never been opened! Have black screen. Looking over the motherboard, straight from factory. All major IC are MOS 83/84 only 2 socketed chips. I'm going to check my power supply first and find a schematic. Wow!
@@TheUtuber999 I fixed 2 of them! Recapped, heatsinks. Swapped RF modulator. Got the VIC 1541 running. Still have 3 to fix. RF modulator kit to build and PLA to install. Most importantly I'm getting good with my tools.
Not gonna lie. I used to love fixing challenging boards like this but now if it has more than a few old bodge wires and missing pads/ traces, I just pull the valuable parts and put it all on a new board.
Ah, that's the one with all the extra features right? I do remember looking at it and thinking it would be fun to check out. Something different to just the plain replica builds - not that doing one of them wouldn't also be fun
@@TheRetroChannel Yeap... I plan on doing one myself, with all modern IC's once I get my hands on a Kawari, and when CBMstuff's XIA (modern CIA) and the Uni64's u6510+64 CPU replacements come out.
Yep, I recently repaired a 250407 rev A board that looked a lot like that. The poor thing was bodge city, and it wasn't even good bodges either. Whoever did it decided to put most of the bodges on the top of the board instead of the bottom. A whole lot of traces were torn off, more or less just like yours. I replaced every single bodge with my choice in wire, which is good ol kynar wire. Then I replaced the PLA and MPU, because they were both bad. The SID is bad too, but I haven't gotten a replacement yet. I'm happy to say the computer lives on to this day.
Nice. I'm a huge fan of the ARMSID, I know ther're pricey compared to the SwinSID varieties but the ARMSID sounds spot on IMHO. And you'll probably pay just as much or more for a real SID, which could die at any time at this point.
Hi, new subscriber here, great content! 😊👍 Can you please share with me/us your LCD type (maybe aliexpress link) that you use in this video? Thank you, and keep up good work
It's a combination of many AliExpress parts, there's a V56 LCD driver board + clear case, an LCD display (I think it's called HJ080), and an LVDS converter board to go between the driver board connector and the panel connector. I will do a video on how it all works... eventually
That magnet wire looks really neat. I think I need to try it out
That beer looks really good and you earned it. Cheers! 🍺
You have more patience than me one look at those bodge wires and id be using it as spares great video
Hmm, almost a candidate for one of those repro PCBs, so much damage.
Thank you for talking about magnet wire. Also known as magwire, this wire is great for repairs or adding traces as part of a mod. Magwire is very popular across multiple industries that repair circuit cards because of the small form factor and reliability. Excellent troubleshooting video.
I’ll definitely be back for part 2.
First time watcher, I saw the title and immediately thought, "this has got to be a later breadbin, 84 or 85, the MOS chips on those were spotty as heck." Then when you opened it up and I saw all of the bodge work and newer chips installed post-factory production, I knew we were in for a ride. Like a Fuck-Me Sundae on top of a Shit Sandwich.
I prefer to use wire wrap for bodges. I'm glad to see someone else who knows that machine pin sockets are the worst. Double wipe sockets are so much better.
Machine pin sockets are good for... machined pins, apart from that I always prefer the dual wipe
I also feel your pain. I am currently working on the same board that came with a few botched wires and some rework done. Grr. I had to walk away. Lol I love your dedication. Looking forward to part 2.
Hope you can get it going, but a parts board is also handy to have if it's driving you crazy
Same to you bud:)
Yeah, I've walked away from a few myself because in my case, and probably the same for a lot of us, we usually have a few nice boards and not enough parts (of the expensive to replace chips like vic or sid) to get them all complete even if we fixed them. The challenge is nice, but sometimes you have to manage your time towards projects with the highest personal reward.
Are you going to get a new board?
I find when using magnet wire that it's much easier to tin the ends of the wire with the iron before soldering it to the PCB or component.
It takes quite while to melt the insulation and you risk damage to the pads while that happens, it's also quite easy to flow solder over the insulation and not realise it's not melted.
Your continuity test would have picked that up though.
The insulation melts quickest if you start with the solder on the cut end, it gets more heat into the copper quicker.
That board is a mess. Yeesh! Not sure I'd have the same patience to rebodge that whole board (unless it was for a friend), but I certainly wouldn't trust the original bodge wires with such a shoddy job it seems was done to this board.
I admire your persistence. I would not even started to try to fix this... your engineering hours are more costly than what the machine worth.
Of curse as an entertainment it is interesting but still...
The ending is the BEST when sitting there with a beer. I think you definitely deserved that :-) Looking forward for part 2 to know what else did you find.
Yep, it certainly doesn't make sense from a financial standpoint and I considered using it as a parts board, but I can't resist a challenge. I did underestimate just how much time it took to get those ICs off, it's much harder when the pads are already missing, and cleanup wasn't any easier. Beers were a must
Yeah, what you do for a TH-cam video vs what you might do for just yourself are not always the same 😃
I really feel your pain. Amazing how precious repair attempts compound the possible range of faults.
It did remind me of that ZX Spectrum you repaired a couple of months ago, especially as a lot of the solder mask on the traces running in between the pins is gone
@@TheRetroChannel so easy to get a bridge on a trace running between those holes. Good luck with the fix!
Very precious repairs.
Definitely be back for part 2, you may just have helped me with a c64 i'm trying to repair, dead test is giving me 6 flashes I swapped out the RAM at u10 and u11 but I'm still getting 6 flashes. U11 was replaced because it had been previously replaced. 👍
Try u22. That's where I read where 6 flashes is:)
Depends on the board revision. Early ones would be U22, but the later ones with only 2 RAM ICs will be U10 (and the other is U11). I'm guessing it's a later one as Tony mentioned replacing U10 and U11. But either way the dead test is indicating an issue with data bit 2, so could be something else corrupting that bit
You are right. Sorry. Still learning:)
Thanks for the advice it won't hurt to change u22 I obvs got confused with revs it has 8 ram chips
Ah, in that case you could also try and piggyback another 4164 on top of U22 and see if you get any result. Just make sure you have good contact between the legs on both chips. I usually push down on top of the one... on top to make sure all legs are touching the one below
Jam in some new 6522s from WDC.
Very cool dude. Can you explain the meanings of the waveforms a little?
The RAM waveforms 14:13 were from pins 3, 4 and 5 (I think). So we're looking at writes to the RAM on pin 3 which happens sporadically, RAS on pin 4 which happens more often at a consistant rate (CAS on pin 15 should look similar), and an address line on pin 5. All of the signals looked pretty standard for a 4164 D-RAM - going between ground and +5V with nothing stuck high, low or in the middle. As DRAM needs to be constantly refreshed, you generally should always see activity if the system is running.
Pin 5 of U25 14:35 (don't remeber exactly what that IC was but it's a 74LS series logic), was sitting around 2V. Like the RAM it should have 0V or +5V, but never 2V. I initially suspected it was a conflict between something trying to drive it high +5V or low 0V, but it turns out it wasn't connected at all, and the reading around 2V was just because it wasn't connected - floating.
The faulty MOS logic 17:52 seemed to work fine sometimes (activity between 0V and +5V) but every so often certain gates would be stuck at 0V. In theory it should have looked the same every time, as I didn't change anything else during power cycles.
I have Commadore to fix and what the hell I'm gonna open it up right now. Couldn't possibly as bad as what I just witnessed. Fingers crossed. 🍻
Good luck with it. I thought this would be another simple fix like a bad PLA. But I turned the camera on just in case it was something different, think I got more than I bargained for
@@TheRetroChannel My God. It's brand new. Never been opened! Have black screen. Looking over the motherboard, straight from factory. All major IC are MOS 83/84 only 2 socketed chips. I'm going to check my power supply first and find a schematic. Wow!
Well at least that's a good sign, hopefully it will be something obvious.
@@patkelley8293 Update?
@@TheUtuber999 I fixed 2 of them! Recapped, heatsinks. Swapped RF modulator. Got the VIC 1541 running. Still have 3 to fix. RF modulator kit to build and PLA to install. Most importantly I'm getting good with my tools.
Ohhh my god you got some work infront of you! Keep up the good work. I see you done haircut looks great :)
Not gonna lie. I used to love fixing challenging boards like this but now if it has more than a few old bodge wires and missing pads/ traces, I just pull the valuable parts and put it all on a new board.
Certainly considered doing the same, but once I got started I couldn't stop
Thank you.
I simply must know where you got that Space Invaders shirt.
I *think* it was from Threadless, but it's pretty old so don't really remember
What an adventure!
That's one way to put it
Looks like a candidate for a new replica board.
I did consider that, but couldn't resist trying to fix it first
@@TheRetroChannel A ICS64S by CBMStuff build would be cool.
Ah, that's the one with all the extra features right? I do remember looking at it and thinking it would be fun to check out. Something different to just the plain replica builds - not that doing one of them wouldn't also be fun
@@TheRetroChannel Yeap... I plan on doing one myself, with all modern IC's once I get my hands on a Kawari, and when CBMstuff's XIA (modern CIA) and the Uni64's u6510+64 CPU replacements come out.
Good video thanks
Also LS245s can be replaced with new LS645s.
Yep, I recently repaired a 250407 rev A board that looked a lot like that. The poor thing was bodge city, and it wasn't even good bodges either. Whoever did it decided to put most of the bodges on the top of the board instead of the bottom. A whole lot of traces were torn off, more or less just like yours.
I replaced every single bodge with my choice in wire, which is good ol kynar wire. Then I replaced the PLA and MPU, because they were both bad. The SID is bad too, but I haven't gotten a replacement yet. I'm happy to say the computer lives on to this day.
Nice. I'm a huge fan of the ARMSID, I know ther're pricey compared to the SwinSID varieties but the ARMSID sounds spot on IMHO. And you'll probably pay just as much or more for a real SID, which could die at any time at this point.
@@TheRetroChannel Yeah I saw Adrian black talk about it. It's just one of those things I haven't gotten around to quite yet. Soon though.
Why the hell did somebody remove all those ram chips and not install sockets? Basically, aren't all C64s from hell?
All of that crap soldering job reminds me of 14 year old me just learning to solder...
Hi, new subscriber here, great content! 😊👍 Can you please share with me/us your LCD type (maybe aliexpress link) that you use in this video? Thank you, and keep up good work
It's a combination of many AliExpress parts, there's a V56 LCD driver board + clear case, an LCD display (I think it's called HJ080), and an LVDS converter board to go between the driver board connector and the panel connector. I will do a video on how it all works... eventually
@@TheRetroChannel Thank you so much for your kind reply. I’m really looking forward for that episode! Have a great day👍☺️
Video uploaded. Like applied. Bookmarked for enjoyment with morning coffee. What a doozy it's looking to be!
Todays kids be like is this the PlayStation 🤣
They just have no idea and its sad.
Did you rly jhust give piggie money?