Computer doesn't work after GPU update

[Remco32]

Hi,

After I updated from a 5770 to a 6950, my computer didn't work anymore. Everything looks OK at start: the MoBo beeps and the Acer logo is displayed onscreen. After this a black screen with a blinking cursor follows. This keeps going on until the fan on the CPU starts to freak out by spinning really fast. When this happens, everything on screen goes black and the computer freezes.
If I try to get into the BIOS, the CPU fan also starts to spin really fast after a couple of seconds, also resulting in a black screen.
If I try to boot with the old 5770 in it, everything goes just fine.
I just got a new 550W PSU, as suggested by my local computerstore.
My other specs:
CPU Type QuadCore Intel Core 2 Quad Q8300, 2500 MHz (7.5 x 333)
Motherboard Name Acer MCP73PV
System Memory 4096 MB (DDR2-800 DDR2 SDRAM)

Any ideas on what is wrong and how to solve it?

 

[user_account_]

My friend it sounds like you may have brought a not so well known make for a PSU which store did you purchase it from and what country you are in. From there I can help you

 

[Remco32]

My friend it sounds like you may have brought a not so well known make for a PSU which store did you purchase it from and what country you are in. From there I can help you

The brand of the PSU is Enermax. I'm from Holland, and I bought it in a local store.

 

[geekapproved]

Did you plug in both of the power connectors from the psu to the video card?

 

[user_account_]

The brand of the PSU is Enermax. I'm from Holland, and I bought it in a local store.

is your card the 1GB or 2 GB model?

 

[user_account_]

Its possible that the amp rails ain't what they should be. Your best bet my friend is that you should take it back and get a full refund then buy one of these. 'http://support.amd.com/us/certified/power-supplies/Pages/listing.aspx'
That is certified and you should have piece of mind. What OS are you running?

 

[user_account_]

'http://support.amd.com/us/certified/power-supplies/Pages/listing.aspx'

 

[ko888]

The only 550 Watt power supply sold by Enermax (but not made by Enermax) is the following :

Enermax NAXN ENP550AWT
OEM: CWT (Channel Well Technology)
Max. Load Combined +12V Rails: 456W (38A)
one 6-pin PCI Express power connector

That power supply's +12V current rating is more than enough to handle a single Radeon HD 6950 graphics card system. It is only short by one 6-pin PCI Express power connector so it will require the use of a Molex to 6-pin PCI Express power connector adapter cable.

 

[Remco32]

Did you plug in both of the power connectors from the psu to the video card?

Yes.

is your card the 1GB or 2 GB model?

2GB

It is only short by one 6-pin PCI Express power connector so it will require the use of a Molex to 6-pin PCI Express power connector adapter cable.

There were 2 PCI powercables in there, a 6 pin and an 8 pin.