Computer rebooting when installing Radeon HD 5770

[r3fl3ct1on]

Hey Techspot,

I recently upgraded my graphics card after running onboard Intel graphics for a week and I bought a HIS Radeon 5770 1GB DDR5.

When I installed the card and attached the power cables to it and booted computer it just starts up and then powers down after 3-4 seconds. Then starts up and powers down and it keeps repeating itself. During this there's no signal to the monitor either. If I unplug the power cables the computer boots up normally but doesnt show any signal on the monitor so have to switch back to onboard graphics.
Is this a power problem ? Read around the net and could see a 450-500W PSU should be sufficient.

Specs:
MSI 945GM2-F
P4 3,6 GHz
Corsair 3x 1 GB DDR2 RAM
ACE 500W PSU
WD 200GB HDD

I only have the HDD plugged in so don't understand if it's really a power problem.

Hope someone can help me out.
THanks in advance

 

[EpicPie]

Your mobo might not be grounded properly or your mobo died.

 

[mailpup]

On the surface your power supply might seem adequate but it could be underpowered or failing. Can you try another, known good PSU to test with?

 

[r3fl3ct1on]

I just bought an OCZ 700W PSU and tested it. Still doesn't work.

I've tried changing motherboard to MSI 915P Neo2-Platinum and it does the same thing allthough the intervals are shorter.

The 5770 card is not faulty as it worked on my gf's brothers comp with just a 450W.

I dont have earth connections on my power outtakes .. is that what you meant about not being properly grounded ??

Really hope someone can help as Im running out of ideas

 

[r3fl3ct1on]

Now I've tried to take out the motherboard and placing in on the box for it. I left 1 memory block and put the graphics card in the PCI-E slot. Attached the 16 and 4 pin power connectors to the board and the 6 pin PCI-E power connector to the graphics card.

Plugged the monitor to the card and tried booting up using a screwdriver to switch on system.

It's still doing the same thing .. booting up for 4-5 seconds then shutting down for a few .. then repeating that cycle.

Tried the same thing with the MSI 915P Neo2 and it does the same allthough only powering up for 1-2 seconds then shutting down.

Is the PCI-E slots dead on both boards ??

Without the graphics card the system with MSI 945GM2-F runs normally. The MSI 915P Neo2 also stays on but don't have any signal to the monitor. (Think I might have disabled the onboard graphics back before my old graphics card died.