computer wont boot with graphics card

[taztheman]

So i have been building a budget gaming computer and once I installed the graphics card the computer will boot. But once I hook up the 6 pin power connector, the computer won't boot. The fan on the graphics card works when the graphics card is just in the pcie slot. I tried the graphics card in my parents computer and same problem when I hook up the 6 pin power connector.
My computer is an optiplex 780
Windows 10
GTX 650

 

[mk378]

Likely not enough power supply wattage, or a bad card.

A business class machine like the 780 isn't intended for major expansion.

 

[taztheman]

It’s a 400w powersupply

 

[daves87rs]

Not sure the 780 is going to handle it....

 

[maxdustington]

Originally Posted By: taztheman
It’s a 400w powersupply


Use a wattage calculator site to find how much you need.

 

[Bottom_Feeder]

You're sure it's not POSTing/booting and not just able to see video?

 

[OneEyeJack]

You need to reset your BIOS. Unplug your power supply, remove the CMOS battery and short the CMOS jumper (CLRCMOS1 located right above the SATA4 connector) for at least 30 seconds then reinstall the battery, boot your computer - it should now boot into the BIOS setup.

 

[taztheman]

Yes, it flashes a red light incidating not enough power.

 

[taztheman]

I’ll try that when I get back home, if it resets the bios is their anything I need to change in bios?

 

[OVERKILL]

Originally Posted By: taztheman
Yes, it flashes a red light incidating not enough power.


Then clearly you need a bigger PSU.

 

[AandPDan]

The "minimum" system spec is 400w for that card. Not all power supplies are equal.

Get a bigger PSU.

 

[taztheman]

But I tried booting the computer with the stock power supply and connected the 400watt supply just to the graphics card and it didn’t work.

 

[faqulars]

take out the video card, power back on and get into the BIOS and disbale onboard video card (depends on manufacturer but basicaly telling the BIOS to boot with your separate video card. power down the system, plug your card back in and see if it works.

 

[NothingNew]

Originally Posted By: taztheman
But I tried booting the computer with the stock power supply and connected the 400watt supply just to the graphics card and it didn’t work.


Did you jump start the 400-watt ps when you tried this? As others have mentioned it may need a different power supply. It's not just the wattage but the brand/quality and the amps on the various rails.

Don't older systems use more of the +3.3V and +5v rails? What are the amps for your ps rails as well as the combined +3.3V and +5V wattage?

Full system specs?

 

[OVERKILL]

Originally Posted By: NothingNew
Originally Posted By: taztheman
But I tried booting the computer with the stock power supply and connected the 400watt supply just to the graphics card and it didn’t work.


Did you jump start the 400-watt ps when you tried this?


This. Unless you jumpered the 400W PSU, it was doing absolutely nothing.

 

[taztheman]

I forgot to jump the power supply, now the computer boots, but the graphics card isn’t displaying video

 

[taztheman]

When i pull it up in device manager it recognizes that there is a card but can’t find updates for the card? Does that help?

 

[mk378]

Set the BIOS to "use add-in card". Plug your monitor(s) into the GPU card not the built-in video.

Do not plug anything into the built-in video. You cannot use both at once.

 

[OVERKILL]

Originally Posted By: mk378
Set the BIOS to "use add-in card". Plug your monitor(s) into the GPU card not the built-in video.

Do not plug anything into the built-in video. You cannot use both at once.


This, or PCI-E as the first display device. Now that the card is working, it needs to be the primary display device.

 

[Linctex]

Originally Posted By: AandPDan
The "minimum" system spec is 400w for that card. Not all power supplies are equal. Get a bigger PSU.


And watch the electric bill go up a fair bit more, too.