[rescue] SUN IPC woes

[Hauke Fath]

Hi,

in the light of the recent IPC PSU thread, I deciced to have a good look
(and take a soldering iron) to the three IPC/IPX PSUs boxed up. One of them
said "ticking" on it, the other "dead", the third "exothermal".

Cleaning up and re-capping brought back to live one of the three. The
"exothermal" one had blown its fuse, and suffered burns on the
transformer's primary side, unsoldering one pin and flat out losing a
second one. I am kind of reluctant to hook it up to the grid.

The second one shows a short blip when switching on, then nothing - a
frequent and mysterious error pattern, it looks. I might unsolder the
transformer, since I practiced on the "exothermal" already.

Anyway - the restored PSU lead to more problems... Powering on the IPC gave me

PROM Checksum test

on the serial line, then silence. Status, or error? When I pulled the
NVRAM, I got

PROM Checksum test
Context Reg Test
Setting Segment Map
Sizing Memory
Mapping ROM
Setting up RAM for monitor.
Setting up memory used in decompress.
Decompressing code to RAM ...
Remapping monitor's virtual addresses to RAM.

and letting it sit over night didn't give me any more. I stripped the IPC
and ran the naked board with one bank of RAM (16 MBytes), no change. No
reaction to a serial BREAK at any time.

Plugging in a sun 4 keyboard, its lights come on, and I get a short video
screen announcing no keyboard was found, and a switch to serial console.

The ROM is v2.9, comparing the eprom content to the image file checks out.

Does this speak to anybody's experience? Any ideas?

Cheerio,
Hauke


--
"It's never straight up and down"     (DEVO)