Computer not working - hardware related

Hi SevenForums users

Im having issues with my PC , first i will explain what the issue is and then what i have tried :

Issue

PC turns on , fans spin up - 10 seconds later - power cuts out

OR

PC turns on , fans spin up - pc stays on but no POST beep and no display

What ive tried to resolve the issue

+ Ran Memtest86+ on my RAM - no issues

+ Ran Seagate Seatools on my HDD - no issues

+ Tested PSU with multimeter - all voltages fine - no issues

+ Swapped over graphics card with an old one to test GPU - other GPU just causes a long continuous beep

+ Tried running the PC in barebones ( just PSU + HDD + MOBO + 1 STICK OF 2GB DDR2 ) and still doesnt work

+ Checked the motherboard for bloated/broken capacitors - all fine

Im really stuck with what else to try apart from take it to a PC repair shop as i dont have any spare parts to test it with but this PC is almost 5 years old (prebuilt acer) and even though it does work for most the stuff i currently do , i dont feel like putting alot of money down on it to repair it due to it becoming "out-of-date" for the want of a better word

Any help is greatly appreciated

Kind Regards

AlanTech

SPECS :

INTEL Q8300 QUAD CORE
4GB DDR2 @ 399MHZ
GEFORCE GT230 1.5GB
OS : WINDOWS 7 ULTIMATE X64 SP1 MEDIA REFRESH

Check the MB battery, and be sure you've checkd settings in your BIOS

PeaB4YouGo said:

Check the MB battery, and be sure you've checkd settings in your BIOS

Changed the motherboard battery and same issue - also - i can no longer enter my bios or anything as i cant get a display to appear

Layback Bear said:

You could try removing the graphics card and using the Integrated Graphics

Acer EG43M Motherboard Specs

Tried removing the graphics card and running on integrated and same issues

Tried my old low-wattage PSU with the system in a barbones setup and at first the pc booted - i had display and everything but then the OS wouldnt boot - i re-tried various things i did before when the pc was working previously via Window's built-in startup repair such as the SFC and CHKDSK commands and it didnt fix anything - i switched back to my old PSU and it booted up which was wierd but then again wouldnt load the OS so i restarted the PC and i was back to the same problems mentioned in my first post

I felt like pulling my hair out earlier lol - i really want to get to the bottom of this

Layback Bear said:

If I understand you correctly you had some success changing power supplies.
Your specs don't show what power supply you are using. Could you add that information to your specs.

It does sound like starting with a new quality power supply. That would be my next move if it was my computer. A faulty power supply can run fans and the such and still not do the other things it's required to do.

I never assume their is only one problem.

The power supply i am using :

400W CiT HE Black Edition PSU with 12cm Fan SATA Power Supply PSU, PSUCIT400HE

and the one i was using on the bare system to test it was an 8 year old OEM 115w PSU

Now it seems to be having the same problem with both PSU's

No post beeps, error codes... either faulty connections or faulty motherboard, double check you seated the connection properly, u know the ones that gives front panel hdd light, power, speaker... the little cables...