I have been repairing an old Apollo 1240 card that has been in storage for sometime.
Some of the pads, and a few of the traces of the dual flip flop chip used to half the oscillator frequency in the 040 position were simply gone. All the vias that supported this chip were also cactus, and needed some form of repair. Typical damage on these cards as the dual flip flop chip is right next to the battery.
Anyways to cut a long story short, I managed to get the chip back in place with a few kynar mods attached.
Plugged it into a 1200 MB with Diagrom in place, and it booted first go
Thought I had a winner so I removed Diagrom and put in my ROMS, and it booted to the insert disk screen. Now for workbench, plugged the IDE device in and yes Workbench booted, but the 16M fastram is not showing up
It shows up in Diagrom but not in workbench ??
So I have tried everything I can think of as follows:
Different ROMS, have tried both 3.0 and 3.1 (different versions of Workbench as well)
Cleaned all the contact mating surfaces a few times (eg. simm connector, edge connector etc.)
Re-seated the MAC chips and cleaned the sockets.
A variety of different 040 libraries.
I have ordered another simm chip, but it has not arrived yet, and I would be surprised if this was the problem as the memory is showing up in Diagrom. (Still I need to try it and it was a low cost item).
Maybe someone has seen this before and can give me a few possible clues what else needs investigating
thanks,
