PC won’t turn on

[Rayy69]

My pc won’t turn on, everything seems to have power and be working ( CD drive works, HDD is working, Cpu fan is working, Gpu fan is working, Psu fan is working, Cabinet fan is working ) , except one thing, the power LED at the front ( blue ) won’t turn on, there is only an orange flash from another LED. HDD led is also off. USB connected devices do not turn on. I have tried removing components and then turning it on, didn’t fix my issue. I have tried clearing cmos, didn’t fix my issue. What else could I try to fix my computer?

HP Pavilion p6-2400sem Desktop PC with a GTX 750Ti

[Grzwacz]

Hi,

Have you verified the monitor works and all connections to the monitor and PC are secure?

You may have a hardware problem. Your PC is about eight years old.

You have to reduce the PC to a minimum configuration and swap known good components to find the bad part.

Power supply failure. Best guess if the monitor and connections to the monitor are okay.

Any component connected to the MB, including front panel stuff or the power switch, or a bad peripheral device such as a discrete GPU. This includes a possible chassis, peripheral, or component short (least likely but possible). 

Motherboard failure or CPU failure (very unusual).

Regards

[Rayy69]

I have given it to a HP Service Center and seems like it’s a Motherboard issue even they aren’t completely sure what went wrong as they did their tests. Thank you for you response, I’ll not be replacing the motherboard as the computer is very old. ( the computer was always kept in good condition, I have cleaned it multiple times )