JJJ

[HAR1122]

PC starts up LED and fans when pressed the ON key, then after around half a min, the fan starts spinning at full speed. There is no display on monitor, I tried changing RAM, resetting capacitors by holding the power key for more than 15 seconds, removed the CMOS battery and kept for 30 seconds to restore BIOS settings but nothing worked till now. The fan spins like its high on coke...

[Grzwacz]

@HAR1122,

A number of things can cause this behavior.

A failing power supply. 

Bad component connected to the motherboard or a bad peripheral connected to the PC.

Reseat all PSU connections to the MB and internal components. Try a different, known good, power supply.

Reduce the PC to a minimum configuration. Disconnect unnecessary peripherals, disconnect the HDD and the optical drive, and disconnect front USB ports which includes the USB 2.0 card reader. 

Try one stick of RAM in each memory slot. Use all sticks, one at a time, to test all sticks in all memory slots. Try a different , known good, memory module in each memory slot.

No luck could mean the motherboard or the CPU (very unusual) has failed.

Regards