DEC Rainbow PC100-A

emanuel stiebler emu at
Mon Jan 18 08:59:42 CST 2016

On 2016-01-17 18:11, Warner Losh wrote:
> Would love to help, but I have the PC100-B. The PC100-A board is somewhat
> different than the
> PC100-B, but not super different.
> Have you checked the diagnostics table in the technical reference to see
> what all LEDs lit means?
> I'd crack open my copy, but it is buried in boxes at the moment.

All LEDs on, means, "replace the system board".

I'm not sure, he wanted to hear that ;-)

> Warner
> On Sat, Jan 16, 2016 at 2:15 PM, shadoooo <shadoooo at> wrote:
>> Hello,
>> I recently took a DEC Rainbow PC100-A.
>> It has been a huge house for a lot of spiders, who deposited eggs and dead
>> insects all around.
>> After full disassembling, cleaning and reassembling, I'm ready to try it!
>> PSU seems to work well, power goes on with almost precise voltages, then
>> all the test leds on the back will lit on...
>> then nothing happens! No video, no sign of life.
>> Clearly there's a problem at the very beginning of the boot phase, that
>> could be caused by a lot of reasons.
>> In the next days I will try to analyze possible causes of the problem with
>> oscilloscope,
>> in the meantime I'm searching a schematic, as board is very complex to
>> follow trace-by-trace.
>> On bitsavers I found a schematic of PC100B, but the main board is not the
>> same as PC100A.
>> Anybody has a schematic for PC100A?
>> I suspect that ROMs could be damaged, anybody has a correct dump to verify
>> the content of the EPROMS?
>> Thanks
>> Andrea

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