18 Jan
2016
18 Jan
'16
7:29 a.m.
On Jan 18, 2016, at 9:59 AM, emanuel stiebler <emu
at e-bbes.com> wrote:
On 2016-01-17 18:11, Warner Losh wrote:
The typical DEC design approach to diagnostic LEDs is that the logic turns them all on at
powerup reset, then the boot / diagnostic ROM turns some of them off as it sequences
through the startup. Typically, the first LED change occurs quite early in that process.
So if all LEDs remain on, that most likely means the CPU is not able to execute
instructions at all. It might mean a busted CPU, busted ROM or CPU bus, or missing power
or clock.
paul
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 ;-)