First post, by Kidrash
Greetings to everyone.
I'm having troubles resurrecting an Olivetti M290s with motherboard M203.
It simply not boot up, nothing on screen, no beeps.
The powersupply was in bad shape, capacitors leaked so the whole power board has been cleaned, neutralized and the capacitors replaced.
Now the voltages are stable but the board still not boot up.
The bios's chips seems to work as they have been read on multiprogrammer and compared with the bios in the collection found here.
The isa diagnostic card show "----", the processor warms up, power is on all the chips on the board.
There is some activity on the board. With a logic proble i tested some lines and there is "traffic" plus with a logic analizer i sniffed some data.
I made an adapter to read the eprom addresses and output (not at the same time, the analizer it's only 16 channel) and the first address i see it's fff0.
It's a bios parted in two chips, high and low, so i don't know exactly how to handle it yet.
Address line seems to be shared with both chips, but not the output. No continuity on the O lines between the 2 chips.
Still with the analizer i tried to sniff some data on the processor and what concern me it's the reset line wich is high almost all the time.
There are some "sparks" of low value in the first 1-2 seconds from powering on but if i read the line after a while it's stable to high.
The reset pin it's connected to chipset TACS82301pb , i can't find any datasheet.
http://www.dosdays.co.uk/topics/Manufacturers/ti.php it's the only information i get googling.
As tools i have a multimeter, the logic probe, the 16ch logic analizer and solder.
What else i can try?
Thanks anyone for any help.