HP Pavilion Slimline s3120n bites the dust.

Ok I'm stumped.

Plug it in press the button. Not much happens. Fans turn on but, Display does not light, No post, no splash, no beeps. Blindly hitting f10 or f anything does not help.

The dvd drive light blinks, the tray opens and closes, but a dvd's inserted don't produce a boot. Ubuntu included.

Tried plugging in an alternate hard drive, no change.

Next step: unplug/remove as much hardware as possible. Drives, network card, RAM, etc.

Try again.

Then add back one stick of RAM.

Tray again.

hmm
wuff- this review seems to think that the cooling is a problem with them. Could the CPU be toast?
Are all the fans working and heat-sinks clean?

Yes when stressed the fans go into "Turbo" mode. It runs hot most of the time.

I sent an email to HP service about the problem describing all the trouble shooting steps, swap drives, reset cards and connections, try a different monitor...

Their response is that the mobo is fried and that I should visit a computer store near me to purchase a new MB with the following form:
* mini-ITX form factor
* dimensions: 19 cm (7.5") x 17 cm (6.7")

The machine was unplugged since last night. Tonight It booted.

After about 90mins. Of software updates and futzing around. Core Temp is reporting 64C.

Started an anti-virus scan which is using approx 50% of cpu time. Temp has jumped to 75C.

Playing multiple YouTube videos pushed the cpu to 100% and the temps to a high of 79C

I pulled the pwm wire from the cpu fan's connector (4 wire fan), forcing it to max rpm's.

The cpu stays below 45c now. But the fan is obnoxious.