P4P800X, power_up, no boot, no beep.

[P4P800X_user]

When connecting a USB photo camera to an USB cable leading to a backpanel USB connector, the computer powered_down.
Repowering only worked after removing and inserting the mains powercord.
However only the PSU and the ventilators in came to live but no boot, beep or harddisk action.

The system was assemble two weeks ago and performed fine on audio, video, stable running and temperatures.
The board however never received -5V as it was not presented by the 24pin 420W PSU. A 24pin to 20pin adapter cable took care of connecting all other power lines, but a -5V was not generated in this PSU.
All was working well, so I assumed the this board without ISA slots was not needing it.

I did read articles about ESD in combination with front USB and ICH5 chipsets and wonder if this could be the problem here.
I removed Optical devices, AGP video card, Memory, Harddisk one by one and started up the system hoping for beeps, but none given.
At each restart attempt, the mains cord has to be disconnected and connected again before the power button on the front was working.

Are there any probing points on the board where I can check CPU activity (reset, accessing devices, ...)?

 

[P4P800X_user]

P4P800X no video, no boot, no beep

I removed the board from the chassis and treated it on a ESD safe layer.
Various CMOS battery actions (removing it for an hour or two, placing it upside down during 20 seconds (ASUS suggestion), swapping CLRTC jumper position during 20 seconds while power is off did not help.
I now also noticed that the ICH5 chip is getting pretty pretty hot.
This is the chip that takes care of the USB ports among many other things.
I can imagine that ESD could have destoyed it. The PC was not connected to ground as the power outlet in the wall did not provide in it. I should have known better as electronic engineer.
Replacing the ICH5 chip is out of the question, it a "little" more complex then swapping the BIOS chip.
Will go for a new board and provide in a proper ground connection for the PC.
Also some education for the end user will be done. First touch some metal ground on the PC (leveling potential differences), then connect or disconnect equipment.

I think that the problem is located and the patient can be declared dead. The topic can be closed.