[olug] OT: Dell Help?

[Eric W. Biederman]

Craig Wolf <wolfout101 at gmail.com> writes:

> Thank you all for the ideas!!
>
> This is a Dell XPS 8940 with a proprietary PS (long square ones) that
> delivers power to the drives through the MB.  Don't have any with that
> style power supply to pull from to test with.  Replacement PS was
> guaranteed to function so there is that...  No lights on the MB when
> plugged in or power on attempted.  MB capacitors are clean.  Both power
> supplies do not have the test switch.
> Last item to test before the MB HAS to be the problem is the power switch.
> I ordered one for $15 to verify if it is the problem child.  Power switch
> has 5 pins so not even sure WHICH ones to short to see if it is the switch,
> hence the purchase...
> Has an Nvidia card and built in video, hasn't made a difference if in or
> not.
> System warranty expired last year so no help there and Dell wants me to pay
> to troubleshoot with them (understandably).

I don't know if this will help, but long ago if the cpu was executing
instructions and starting to boot (but failed somewhere along the way)
you would get a beep code.

Is that something modern motherboards still do?

Part of me wants to suggest connecting some probes to the ROM chip and
see which instructions (if any) are being read by the cpu.  Usually
those chips are LPC which means their max clock rate is 33Mhz and the if
memory serves the bus has about 4 pins, which makes it easy for a logic
analyzer to decode their signals.  But that is a technique for suited
motherboard bring up rather than debugging some random motherboard.
Simply because not many people have logic analyzers laying around.

Eric