Pressing power button and PC not starting. HP AiO 400g2 non-touch

[stsin105]

Hello,

I have issue with HP AiO 400g2 non-touch.
When i press power button only led lights anything else not start.

Mother board receiving power

I try to replace DC Cable, CPU, RAM, I try remove BIOS Battery, unplug and plug all cables.

I also try "press 30 second", Please don't suggest that.

Yesterday when problem was occurred, I teardown it and instantly power on when i press button, after teardown.

Today morning, when i try to turn it on, it was same as yesterday.

Teardown wont help at this time.

Can someone tell me what's the real problem here?

Maybe motherboard?

[itsmyname]

Maybe motherboard. Does it start when "cold" (powered-off all night)?

Maybe on/off button, but not likely.

Maybe power-supply. If you can do a "tear-down", you have the skills to try a different power-supply, with a "bare" system:

* keyboard

* video-cable

* disconnected data/power cables to disk-drive and CD/DVD

* power-cord

to see if can successfully POST (Power On Self Test).

[stsin105]

Thank for reply.

I try as you said but result is same.