Green LED on back indicates power, Turns off immediately upon hitting power Button

[MJA01]

Green LED on back indicates power, Turns off immediately when hitting power Button

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Product: HP Envy Desktop 750-537cb

13 months old and when we hit power button nothing happens except green power light on back goes out. We have to unplug power cord in order to get green light on again. Power supply tested OK but replaced it anyway, disconnected and reinstalled cables and ram but still have the same problem.

[Grzwacz]

Hi,

You have a system short if the power supply is shutting down and unplugging the PC resets the power to the system. It is probable the original power supply is okay if you replaced and have the same problem.

Reduce the PC to a minimum config (RAM, CPU), this means disconnect all other components (Front USB, HDD, DVD, front USB card reader), then check for power and POST after disconnecting one component at a time.

The motherboard could also be shorting out which causes the power supply to shut down.

Regards

[MJA01]

took your advice and unplugged everything on the board and took out video card but still had same problem.

I reinstalled everything, testing again after each re installation with no improvement.

Once everything was reconnected I pulled the processor and the green light stayed lit and everything fired up- Fans, drives,etc.

Do you thinks a bad processor or motherboard?

[Grzwacz]

Hi,

Good troubleshooting, I forgot to mention removing the graphics card, if applicable.

It's one or the other. The only way to isolate would be to try a different, compatible CPU in the factory MB or try the factory CPU in a different, compatible MB.

MBs usually fail before CPUs but it is interesting you had continuity after removing the CPU. Did you check the CPU socket for any bent pins?

If anything connected to the power supply is shorting to ground the power supply will shut down to protect the system.

Regards