Computer shutting down.

Gigabyte GA-8I945PL-G mobo
500w easy cool power supply.

All hardware and cabling has been removed except CPU / Heatsink / Fan and cables to use on/off button and LEDs.

At POST computer gives continuous short rapid beeps indicating power issue.

Tried with 350w, 450w and 500w (usual one) power supplies - all give same result.

Removed, checked and replaced mobo - no apparent shorting going on.

Removed and reseated CPu heatsink and fan - no visible issues and is correctly seated.

reconnected main (24pin) power cable to board and 4 pin ATX power cable.


What else can I check for?
Does anyone have any ideas that may help.
What are the possibilties that I haven't covered yet?

Thanks

webecho

check your memory card..or try using a new one

Was this computer ever running or is this the first time you have fired it up?

When you reseated the PCU did you reapply thermal compound?

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.