Hello everyone,
I'm working to troubleshoot a 286 laptop style computer. I've kind of
hit the end of my knowledge and wondering if anyone has any insight.
The computer in question I've never seen run. So I don't know normal
behavior. There were a few caps inside that were leaking electrolyte, I
cleaned it all up and replaced them. A few traces look a little bit
corroded but test fine.
First thing I'm thinking, is did the BIOS eproms loose a bit or two of
data from age? Bit rot? I did read off the two BIOS chips (high and low
pair I assume.) I can see text like Copyright Pheonix Technologies 1988,
but I can see that for instance the first character of the text Copyright
is wrong, it's a P in one file and 9A in the other.
Second thing I hooked up Oscope and cut on computer. It never does a
floppy seek. When I poke around the 27c256 EPROM I see constant activity
on all address lines, and all datalines. This includes the OE pin as well.
Would a normal runnng computer hit the BIOS that much?
Any thoughts appreciated!
--
Ethan O'Toole
