I know this thread is very old but since I run in the same trouble, I'm going to leave here some info about why this issue happens and how I solved, just in case anybody would need.

I had the same problem with all of my GAL20V8B:

most of the times I got a protection error, something like chip ...

My two cent about it, hope it can help somebody.

I recently bought 5x 1581 replica boards from PCBway - shared project ("Commodore 1581 Enhanced", something like this).
I've built two drive using what I have in my toolbox: 8520 and 1772 and the official ROM v.2 (and a 3D printed replica case ...

Hi all,

I have an 8032-sk with a working board (some minor issues, though) and a CRT that suddenly stopped to work.

I'm sure the problem isn't the board or the connector or the power, because I swapped the monitor with another 8032-sk I have and it works.

Clues:
- It worked fine until some days ...

Ok people, after many troubles, I successfully repaired the original 3032 board, thanks to the help of some friends from 6502.org and http://www.vintage-computer.com forums. I tried to fix it for the first time in 2001; I tried many times to get the rid of it without luck; then you people ...

OK, I still find it difficult to navigate all the files listed on that site. But I did a google search of the site and found this text file . It says "this SCH is valid for the 3008 to 3032. It is just a matter of placing the right 'jumpers' and RAM-ICs."

I have not reproduced the entire text ...

Any idea? Back to basics. Have you measured the 5 volt supply -- recently, I mean?

I did it after replaced the old capacitors of the rectifier section with new ones, but I will measure it again, just to be sure...

Do you have access to an oscilloscope or logic probe?

no :-( Just multimeter ...

I checked all of the existing sockets (I mean the original ones from Commodore that's actually hosting an IC); luckily a little part of the soldered trace was accessible by the multimeter probe, so I was able to check all of them. I found the 6502 socket was faulty. For I while I almost hoped in a ...

Yes, same part number: 6502

I did the test you asked me:
- all the 6502 work in the 8032
- all, except one, produce a garbage screen in the 3032. The different one produces a garbage screen for about 1-2 secs., then the screen become suddenly black. If I switch off and then on again rapidly ...

All 6 chips are presently known to work in the 8032? And, in the 3032, 5 chips are presently known to leave garbage on-screen, while the reamaining chip clears the screen to black -- is that right?

Are the chips superficially similar, identical, or what? And "CMOS"? I don't recognize that as the ...

the garbage appears for a couple of seconds, then disappear and the screen become black. That might very well be the correct initial behavior. Incomplete, perhaps (due to some additional problem elsewhere), but correct. As I said, I don't have any CBM background. Anyway, you have two CPUs that ...

...of course to repair the 3032 is the best (and my preferred) choice.

Swap the boards and the CRTs was just an alternative way to make the 3032 to work using what I have at home.
Honestly, my desire is to fix the 3032 board!

That's the situation: I have a 3032 board where every IC is socketed. I ...

I tried to directly connect the 8032 board to the 9" monitor but the result is a messy screen, something like when you to connect a 1280x1024 VGA card to an old CRT monitor with a max resolution of 1024x768... you can still see something, but messy. Ok, no surprise. The horizontal (?) scan ...

Hi Jeff, thank you for your answer!

IOW, take the 8032 board and dumb it down to produce 40-column video signals that the CRT assembly from the 3032 will accept?

exactly. I know that CBM did the 4032 and 8032 series using same or very similar boards. So, maybe, there's a way to change something ...

Hi all,

this is an alternative question to my previous post, "CBM 8032 board into a CBM 3032 case/monitor?", since I'm looking for an alternative exit from my troubles...

Resuming: I have a spare, working 8032sk without keyboad and a faulty 3032 I'm one step away to fix it use gasoline and a ...

Hello,

I have a faulty CBM 3032 (garbage screen) I'm trying to fix since 2001 with no result... I've changed *every* chip on the board: ROM/RAM/CPU/VIA/other damn'd without luck. The problem persists so I think maybe I added another problem instead to fix the old one...

Since I have a spare 8032 ...