Long time ago I aquired an spare LC motherboard which I safely put away and forgot about it. As far as I remember it was sold as non working. Upon getting the board I removed all caps, right before they started leaking. Only one pad was lost. Recently I recapped my LC475 and wanted to attack the spare LC board. So I installed new (tantal) caps onto it and fired it up. It chimes but then it "dead chimes". There is no video at all.
I remembered a video by Adrian Black which talks about a serial diagnostic method on 68k macs. According to https://docs.google.com/spreadsheet...LH6ruCiAVE/edit?gid=1705532296#gid=1705532296 the LC does not see any RAM at all. The error code 0011 leads me to believe this. If I try to store some values into the RAM I always get back FFFFFFFF.
If I check the RAM chips with my cheapo oscilloscope the lines A2 and A5 look noticible different than the other lines. There are no broken traces as far as I could check them.
I dont know how common RAM errors are on the LCs but I dont think that all the memory chips are bad. I suspect the two LS245s which are the bridge between the memory and the rest of the computer. Is this a common fault?
I remembered a video by Adrian Black which talks about a serial diagnostic method on 68k macs. According to https://docs.google.com/spreadsheet...LH6ruCiAVE/edit?gid=1705532296#gid=1705532296 the LC does not see any RAM at all. The error code 0011 leads me to believe this. If I try to store some values into the RAM I always get back FFFFFFFF.
If I check the RAM chips with my cheapo oscilloscope the lines A2 and A5 look noticible different than the other lines. There are no broken traces as far as I could check them.
I dont know how common RAM errors are on the LCs but I dont think that all the memory chips are bad. I suspect the two LS245s which are the bridge between the memory and the rest of the computer. Is this a common fault?
