Really to be honest when an A/B comes in.. I don't even diagnose it.
I just get right on into it... Clean, Do the caps, suck out all the cracked joints, then test. and from there, it either works fine or it does not, if not, from this point i can make a good estimate as to what its going to still need to work properly as far as time/costs.
As i said in this thread:
https://68kmla.org/forums/index.php?/topic/21632-macintosh-plus-boot-problem-maybe-a-cracked-solder/page-4
I just get right on into it... Clean, Do the caps, suck out all the cracked joints, then test. and from there, it either works fine or it does not, if not, from this point i can make a good estimate as to what its going to still need to work properly as far as time/costs.
As i said in this thread:
https://68kmla.org/forums/index.php?/topic/21632-macintosh-plus-boot-problem-maybe-a-cracked-solder/page-4