FAULT FINDING & REPAIRING THE SUPER CPU 64
I recently bought a Super CPU 64 from a guy in the USA on EBAY.
It was being sold with the "Buy it now" option and it was selling as "WORKING". But it did not come with the DRIVER disk from CMD, so I had to just try it out by playing GAMES and using various UTILITIES, and it did speed everything up and I was very excited but then I was not sure if the 16MB RAMCard was working or not ?
The first test program I got my hands was actually a DEMO called "SUPERCPU KICKS", it needs a minimum of 1MB of SuperRAM. I have 16MB so it should run on. I loaded it and then watched as it copied ALL 3 DISK SIDES into the Super CPU RAMCard. It then RUNs the DEMO, and if your RAM is working then so does the DEMO.
After only one minute, the DEMO crashed and I thought it was not a big deal, but it still had me worried.
I then managed to find a copy of the CMD-SUPERCPU DRIVER disk. It contained a few TEST programs.
The first one I loaded was SUPER RAM CARD, it found the 16MB & RAMCard, so that was ok.
Next I loaded SUPER RAM TEST, and it failed about half way through, Reporting that the 16MB SIMM is not properly seated in the SIMM socket, or I may be using the wrong TYPE of RAM, ie- DONT USE "EDO", only use FAST PAGE RAM.
The RAMCard had Hot-melt Glue on one end so it had been repaired very poorly. the repair was so poorly done that I had to desolder the 72-pin simm socket and replace it with a new one with metal end clips. But this did not solve the problem.
At this point I started testing ALL the Chips on the Super CPU 64 - Motherboard and the RAMCard.
I ended up borrowing a friends Super CPU 128 and this allowed me to determine that the RAMCard had the fault , not the Super CPU 64 - Motherboard. I then concentrated on the RAMCard.
I was able to de-solder & Test every Chip on the RAMCard and NONE were faulty , thank god, so it had to be a connection issue.
I tested the 60-way JOINER that connects the SuperRAMCard to the SuperCPU64- Motherbaord, but it was ok.
I then noticed one of the pins was bent down on the New 72-pin connector, talk about bad luck, You would never expect a New part to be faulty or damaged but it was. I heated & bent this pin back to the right position, inserted the 16MB SIMM and now it is working 100%
REPAIR
As a result of my testing 100% of the Super CPU 64 , I fell I now have a very good understanding of all the inner workings. And I also have the ability to test the funtionality of all the Chips in the unit, So if anyone needs help reparing their Super CPU 64/128 , then fell free to email me , I will do my best to help you.