[Tfug] Power Problem (slightly OT)

[Choprboy]

On Tuesday 22 January 2008 14:17, Jim Secan wrote:

> More info.  There's a power LED towards the bottom of the MOBO.  It's on,
> and solid green, which I believe means that the MOBO thinks power is on
> and OK. 

Actually, that probably means that the motherboard is correctly receiving the 
+5Vsb rail from the powersupply. This should always be on, indicating the the 
BMC (Baseboard Management Controller, typically a small PIC or dedicated 
purpose circuit) is powered. The BMC does things like watch the front panel 
contacts for power/reset presses and then grounds the PSON from the power 
supply or holds down the CPU reset line. It also typically does things like 
watch chassis intrusion switches and act as an emergency shutoff if 
temperature goes thru the roof. 

> Last ditch desperation - does anyone know if there's a BIOS control on
> this thing that might have it locked up, and if so is there some way to
> reset it?  I've pulled the power plug several times to no avail.  I see
> this beast has an on-board battery - (1) would a dead battery cause all
> this mayhem, and (2) if I pull and reset the battery might that reset the
> BIOS ROM?

Possibly and Yes. They should probably also be a jumper label "BIOS" 
or "PASSWD RESET" or something like that, that also resets the BIOS. A 
completely hosed BIOS could cause the problem I suppose, though I wouldn;t 
think of it as a high probablity.

Adrian