Bun's Lab
First power on and wiggling a bit at the memory Simms. No beep. Guess it's a project. I don't have the time for it right now though, so I'll put it back together and put it on the ever growing pile for now. All I wanted to do is neutralize the battery leak…
So, the post codes can mean wildly different things depending not only the BIOS maker but also version. Older AMI BIOSes up to 1991 point to a memory issue. Newer ones up to 1993 to something completely different. This 74F00 hex inverter is of course highly suspicious, as are two or three traces coming from the chipset.
Source: http://mrbios.com/techsupport/award/postcodes.htm
Source: http://mrbios.com/techsupport/award/postcodes.htm
Mrbios
POST Codes
Mr. BIOS by Microid Research was a technology service company offering a array of BIOS related consumer services.
Bun's Lab
So, the post codes can mean wildly different things depending not only the BIOS maker but also version. Older AMI BIOSes up to 1991 point to a memory issue. Newer ones up to 1993 to something completely different. This 74F00 hex inverter is of course highly…
Ahh, I couldn't resist. Got a late night urge to fix this thing.
🔥1
This NAND is definitely bad. Three gates don't do what they should. Their inputs are low, but so are their outputs. Only one gate was working. Problem is, the holes are so tight that it was impossible to get it out without cutting it off.
😢2
Bun's Lab
This trace is also bad
Continuing: this alone didn't help. Still broken.
Bun's Lab
Photo
Because the RAM slots were so badly affected, I ended up tracing them out.
Everything checks out, including the 74F244 buffers to the RAM. /CAS however is perpetually high after a short burst of activity during start up, so there is never even any access to the RAM after that.
Everything checks out, including the 74F244 buffers to the RAM. /CAS however is perpetually high after a short burst of activity during start up, so there is never even any access to the RAM after that.