Post by hydrophilic on Mar 29, 2016 2:30:17 GMT
Yes, the one in the photo labeled "CIA2" is what most people would call CIA #1. I can't really see the part numbers on the smaller chips, or I would tell you which of them to check....
Wow, your CIAs are not socketed? That would be a MAJOR pain to replace! Especially if you do not "know" that CIA is the real problem (remember, it could be a support chip, instead).
I guess that is one way for cost-reduction: eliminate all sockets (or most).
I have original/flat C128, but sadly the 8502 and Z80 are not socketed... so many times I thought about building a simple/stupid "computer" with one of those chips, but never did because they are soldered in place. Oh, sorry about that... drifting off-topic...
Anyway, I've pointed you in the right location, but I can't really give trouble-shooting tips unless I do some analysis and you have good understanding of TTL-logic (gates / states / testing procedures). Only thing I can suggest off the top-of-my-head is to use one the "SAMs" trouble-shooting / service manuals available on Bombjack... or try one (or more) of Ray Carlsen's trouble-shooting guides...
Best of luck, and let us know what happens! Even if you can't find a solution, knowing what steps FAILED to work will be very informative...
Wow, your CIAs are not socketed? That would be a MAJOR pain to replace! Especially if you do not "know" that CIA is the real problem (remember, it could be a support chip, instead).
I guess that is one way for cost-reduction: eliminate all sockets (or most).
I have original/flat C128, but sadly the 8502 and Z80 are not socketed... so many times I thought about building a simple/stupid "computer" with one of those chips, but never did because they are soldered in place. Oh, sorry about that... drifting off-topic...
Anyway, I've pointed you in the right location, but I can't really give trouble-shooting tips unless I do some analysis and you have good understanding of TTL-logic (gates / states / testing procedures). Only thing I can suggest off the top-of-my-head is to use one the "SAMs" trouble-shooting / service manuals available on Bombjack... or try one (or more) of Ray Carlsen's trouble-shooting guides...
Best of luck, and let us know what happens! Even if you can't find a solution, knowing what steps FAILED to work will be very informative...