linuxlove
Veteran Member
I think you should leave them right there. Thats Kitchen Chic that is :D
But what if he's married? What would the wife say about the systems?
I think you should leave them right there. Thats Kitchen Chic that is :D
Geez, where else does a pinball machine belong if not in the living room???
I added a few questions; also, does it beep when it starts up (in either state)?
Yes it does have the normal 4tone boot sound on power up.
It's really frustrating trying to remotely troubleshoot if you don't answer our questions...Yes it does have the normal 4tone boot sound on power up.
It's really frustrating trying to remotely troubleshoot if you don't answer our questions...
Again:
- If you allow at least 10 seconds between power off and power on, does it still come up randomly in either of those two (and only those two) states?
- Once it's up, if you do nothing do both displays remain the same or do any locations change at all?
- If you type something or just hold down a typing key, do either of the displays change at all?
(I take it that even after holding the space key (for example) for ten seconds or so there is never a beep?)
and
- Which ICs did you replace?
Looks like it's more than just a video problem then; if you still get the Commodore BASIC message that the first screen shows but the keyboard isn't recognized then I'd suspect one of the ROMS. Looks like it passes the RAM test but goes off into never-never land some time afterwards.With 10sec between power ups it 9/10 comes up onto the first screen. These screens never change and there is no active data in them, they remain the same. There is never a beep and nothing changes if typing or holding down a key till what would usually reach the end.
I replaced all the DRAMS, SRAMS, the 74LS244's in ram section and the 373's in the RAM section. This made no change in the screen. I also swapped the 6502 no difference, and the character rom no difference.
Thanks
Sounds like you've got a programmer; if you've double-checked all the sockets and pins maybe it'd be worth while to read them and make sure they match the correct numbered images on Zimmers. You show both systems; I take it that this is the one with the EPROMS? 2532s except for a 2716 in UD7 (E0-8 )?
OK; looks like we're sort of back where we were; I'd suspect UC6 and/or UC7.
UB6, UB7, UB8 are all socketed. I'll check them in my IC tester shortly. UC3 is not and as fate would have it I do not have a 74LS138 in my stock.OK; looks like we're sort of back where we were; I'd suspect UC6 and/or UC7.
Edit: I see that you did replace the video RAM; did you replace all 4 and nothing changed? 9114 should be an OK replacement.
If you did indeed replace all 4 and there was no change then I'd suspect UB6, UB7, UB8 and UC3 in that order.
What does it look like with UC6 and UC7 removed?
I'd suspect UB6, UB7, UB8 and UC3 in that order.
Excellent! Glad to see another PET resurrected.Ding Ding we have a winner, UB6 when tested in my checker came back as a 74LS185 not a 74LS244. Swapping this fixed it up. It now displays properly! Thanks so much for your guiding me through this.
John
What part of the world are you in BTW?