Black Screen No POST With Graphics Card; No Problems With Onboard Graphics Card

Toastrbrot123

Commendable
Aug 8, 2016
1
0
1,510
Hi,
in the last week i had issues (hardcrashes) with my computer like described in this thread (http://www.tomshardware.co.uk/answers/id-1735622/random-crashes-randomly-colored-screen-computer-unresponsive.html) while playing StarCraft2.
I tried to fix these by cleaning the fans, increasing the fanspeed, memtesting and reducing the clockrate on my graphicscard.
Sadly today the pc crashed again but this time i got a blackscreen at booting with no POST beep. So i started breadboarding until i realized that i got an onboard card on my mainboard and tested it. The computer ran perfect. To test it i put the card back in with the same result: computer runs but I got no POST beeps.

So my assumption is that I got a defective PSU which can't supply my computer when the graphics card is connected. Sadly I'm a poor student with a tight budget with no spare PSU or graphics card to test this.

My question is if my logic sounds plausible and I need with high probability a new PSU or could the error still be at another part of my hardware?

Thanks for any help I can get


My Computer:
Operating System
Windows 7 Ultimate 64-bit SP1
CPU
Intel Core i3 2120 @ 3.30GHz
RAM
4,00GB Single-Channel DDR3 @ 665MHz (9-9-9-24)
Motherboard
ASUSTeK Computer INC. P8H61-M LE/USB3 (LGA1155)
Graphics
Radeon HD6870
PSU
Corsair VS450W
 
Solution
If the psu was defective, it'll shut down. Not blackscreen. It's either the gpu that's toast or the pcie buss for that slot (in other words the motherboard itself). Since the LE is the bottom grade motherboard (I have a p8z77-v LE) and there's only the one pcie x16 slot on your board, its hard to test this without borrowing a friend's gpu.

As it stands, the HD6870 should have a minimum 500w psu and that VS is not a good quality unit. But, it'll run the gpu in low power settings like boot, Windows, Web surfing etc. If you've been gaming it's very possible the card is burned from lack of power, bad outputs etc, or the card could have been over drawing the pcie x16 slot and burned the mobo.

You'll really need another gpu preferably...

Karadjgne

Titan
Ambassador
If the psu was defective, it'll shut down. Not blackscreen. It's either the gpu that's toast or the pcie buss for that slot (in other words the motherboard itself). Since the LE is the bottom grade motherboard (I have a p8z77-v LE) and there's only the one pcie x16 slot on your board, its hard to test this without borrowing a friend's gpu.

As it stands, the HD6870 should have a minimum 500w psu and that VS is not a good quality unit. But, it'll run the gpu in low power settings like boot, Windows, Web surfing etc. If you've been gaming it's very possible the card is burned from lack of power, bad outputs etc, or the card could have been over drawing the pcie x16 slot and burned the mobo.

You'll really need another gpu preferably smaller draw, to test.
 
Solution