[vcf-midatlantic] Pet Help

David Hoelzer dhoelzer at enclaveforensics.com
Fri Jun 28 18:01:43 EDT 2019


Hey-

 

My life is still in turmoil, but I decided to have a go at my PET before moving it on to a new home (yes, some of you know who I'm looking at).

 

At this point, it is semi-conscious again... but...

 

I appear to have a strong clock, phi1, phi2, and there appears to be data appearing on the data lines of the 6502 (see the logic analyzer output).  The display, however, is not happy looking.  Additionally, while the display in the photo looks awesome (compared to complete darkness), it will randomly flicker to darkness or perhaps even go dark for long periods.  Nothing is particularly hot on the board, I just burned a complete set of EPROMs (and verified them), and I've been over the board three times looking for solder joints, etc.

 

When the screen goes dark, the tube is still glowing, so I'm guessing that it's a video circuitry problem, but I'm stumped as how to tell if it's on the board or on the CRT board.  (This is a 2001-N 32k..)

 

Any suggestions?  I know we have some PET pros around here.  Photos attached.  If they don't go to the list (I don't remember of they do) ping me and I'll send them direct.
 

 


 

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David Hoelzer
Chief of Operations
Enclave Forensics, Inc.

 


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