[rescue] SS10 CPU detection problems

[Ethan Hawke]

> Hi,
>
> I own a SparcStation 10 with two 390Z55 (501-2352 SM51) CPU boards.
> It used to happily come up with both, but recently it sometimes
> drops into firmware with a Watchdog Reset, and reports only
> 1 X 390Z55.

Sorry to hear about your SS10.

It's sounding like dirty or damaged contacts to me.

> I've tried to find out which of the boards is bad, but it gets even
> more strange from there - the system won't do anything at all with
> only one of the MBUS slots populated (I get one keyboard blink, but
> the system LED stays off, regardless of which CPU I use). Same when
> I swap both boards around.

When trying a single CPU, make sure it is in the lower slot as
the upper slot is disabled on Power-on, and the CPU on the
lower slot must enabled it first (which can't happen if it is
missing).

The system LED is under software control and is turned on
very early during POST, so is a quick indicator if the machine
will not POST.

Good luck,
Ethan