Recent content by Stephen_Usher

This 3D printable bracket is ideal and designed with the SE/30 in mind as much as anything: https://www.printables.com/en/model/436327-bluescsi-v2-hard-drive-bay-bracket-rc2

Well, it does say RESET on the solder mask, so I took it at its word.

Thanks. I was actually mistaken, the system was holding the settings but I didn't realise that the motherboard RESET also reset the NVRAM. :)

Thanks! Very helpful.

I've got a battery damaged LCIII almost completely operational. The original battery holder (long gone) has been replaced with a CR2032 with the positive side connected to the remains of the + connector for the battery holder. However the system isn't holding its settings. Unfortunately the...

Thanks. Unfortunately the battery isn't keeping the NVRAM alive, so i need to find out where the power goes. Unfortunately it seems that the Bomarc schematics totally left this out.

After pressing on the CPU and getting different results, reflowed the lower address lines on the CPU and... Success!

The machine now constantly cycles crash/reset but it's inconsistent, depending upon whether D0 is high or low at the end of the sequence. If D0 is high then the CPU quiesces for a while before restarting. If it's low then it immediately restarts. R/W on the CPU is constantly high, as is /BERR...

I've got a little further with the diagnosis. After replacing the HI ROM socket with a new one as the contacts on the original were corroded there was no change, but I noticed that D20 and D21 looked strange so lifted the D21 leg. This looked good when out of the socket. Checked D21 on the PDS...

Further investigation shows that the CPU is reading the first two words of the ROM and then reads an address with the same lower nibble as the second word of ROM, which would be an instruction fetch for the ROM entry point. It then reads another word from the next address and then tries to read...

I've been handed an LC III which had some localised battery damage but the CPU pins got damaged and the previous owner tried to fit a new CPU, got stuck and handed me the machine. I've replaced the CPU with another one and although it doesn't look great all the legs tone out correctly...

Thanks.

Thanks, but shipping a single screw across the Atlantic would be prohibitively costly. :) If I knew the thread size and pitch and the length I should be able to easy get one in the UK.

Does anyone have the specification (thread/length) of the screw which holds the floppy/hard drive cage onto the base of the case in the IIci? It's missing from the machine I have and would like to find a replacement.

I've recapped the low voltage side of the PSU. They were all leaking even though they were Nichicon. Well, all but one cap, C23, which the posting giving the capacitor specs said was 47uF 16V and actually it should be 100uF 35V, so I had to put the original leaking cap back. Unfortunately the...