my hp computer turn on for a few seconds then turns off.

[Neptunestar]

my hp pavilion desktop computer turns on for a few seconds then turns off. Power button light flashes, both fans move for few seconds. but HDD do not start and not HDD light with power button light. Also, Power supply unit light (at the back side of PC ) goes off like power button light.

After removing PSU cable from back of the PC, long pressing power button again move both fans and flashes power button light in front of PC. 

Please help. 

[Bill_To]

Hi @Neptunestar 

This symptom usually indicates a power supply problem.

Or the PSU is shutting down due to a problem with a component or peripheral connected to the MB.

Or the MB or CPU is in trouble.

You have to troubleshoot all components in the system which may require using replacement parts. Or have a local PC tech take a look to find the bad part.