Login

Back to forum Reply to this topic Go to last reply Posted By Chrom_ on 2016-10-15 14:19:46  Suggestion for repairing a Commodore Plus4 I'm trying to fix a Plus4 and looking for some suggestions. Plus4 would turn on, display picture, but after 10-15 minutes of operation: - lose video signal for a second (composite) - reset itself randomly I have replaced the capacitors and reseat CPU and TED, with no success in fixing the problem. After a while operating in these conditions, the screen suddenly went garbage, and then black. Since then it's displaying only black screen. My guess is shorted TED or CPU. I have noticed that CPU and TED replacements are quite expensive, so I don't wanna go random. Any suggestions to better identify the fault? Posted By gerliczer on 2016-10-15 14:51:06  Re: Suggestion for repairing a Commodore Plus4 You may burn an EPROM with Diag264 software and put it in the Function low ROM socket (U25). You may even try to buy a complete test tools set from the creator of Diag264 or build your own. You may even run oscilloscope and logic analyzer tests based on the official troubleshooting guide or system technical manuals you can find at Bo Zimmerman's site. Posted By Chrom_ on 2016-10-15 16:02:36  Re: Suggestion for repairing a Commodore Plus4 Doesn't DIAG264 run from inside the plus4? In my case I don't think it's gonna work as I only have a black screen at powerup... Back to top Reply to this topic Copyright © Plus/4 World Team, 2001-2025. Support Plus/4 World on Patreon