CBM 8032 not working - Screen full of zeros
Posted: Wed Jul 18, 2007 8:16 am
Hello,
my brother few days ago rescued a CBM 8032 from being sent to the garbage dump. It's now placed in our playroom along a pair of VIC-20 a C64 (VIC20-style case) another C64 (Amiga-style case) and 2 Amiga 500 besides few other interesting old piece of machinery.
The 8032 seem to be in quite good condition (i haven't been home since its arrival, I just saw a photo of it and talked to my brother) although it's missing the front black label...
Now here's the problem...
At the first boot it seemed to work fine (the photo above refers to it) but some characters were not displayed correctly when typed. We thought about a problem with the keyboard connector, perhaps oxidised contacts...
But after few reboots the screen started to appear filled with zeros with the system messages messed whithin that sea of zeros.
The messages can't be read since they aren't displayed with the correct characters but you can tell that they are there. For example the "ready." statement appears as 6 strange characters at the beginning of the line.
The system seem to be functional but the display is all messed up.
We hypothesize (according to a Commodore troubleshooting chart)
that the problem could involve one or another of these components: the Complex Interface Adapter, the Programmable Logic Array, the VIC II processor or a power supply problem.
What could possibly be wrong? How can we try to fix it?
Thank you in advance
Regards,
Ronin - Italy
my brother few days ago rescued a CBM 8032 from being sent to the garbage dump. It's now placed in our playroom along a pair of VIC-20 a C64 (VIC20-style case) another C64 (Amiga-style case) and 2 Amiga 500 besides few other interesting old piece of machinery.
The 8032 seem to be in quite good condition (i haven't been home since its arrival, I just saw a photo of it and talked to my brother) although it's missing the front black label...
Now here's the problem...
At the first boot it seemed to work fine (the photo above refers to it) but some characters were not displayed correctly when typed. We thought about a problem with the keyboard connector, perhaps oxidised contacts...
But after few reboots the screen started to appear filled with zeros with the system messages messed whithin that sea of zeros.
The messages can't be read since they aren't displayed with the correct characters but you can tell that they are there. For example the "ready." statement appears as 6 strange characters at the beginning of the line.
The system seem to be functional but the display is all messed up.
We hypothesize (according to a Commodore troubleshooting chart)
that the problem could involve one or another of these components: the Complex Interface Adapter, the Programmable Logic Array, the VIC II processor or a power supply problem.
What could possibly be wrong? How can we try to fix it?
Thank you in advance
Regards,
Ronin - Italy
