My conclusion was that a problem is with power on/off module on the mother board. I have disassembled everything: RAM, HD, monitor, CD, keyboard, speakers, media buttons, mouse, external connectors and power button harness as well. Remained just motherboard (with CPU, GPU, cooling unit, ventilator, BIOS battery) and external power supply. I make short shorting on connector of power button to power it on, but nothing new - after 5 seconds it switchs itself off like power button is still kept pressed.
I was suggested to run Combofix tool to eliminate the software problem, but nothing wrong were found there. There is a link to Virus Removal forum, where I have started a treatment: My link
Is any idea how to fix or bypass this issue? Any suggestion will be appreciated!
Edited by alexanderudler, 31 July 2012 - 04:45 AM.