View Full Version : My graphics cards kill all output - any advice?

21-02-2015, 03:33 PM
I have an HD 7750 (Sapphire) and a GT 440 (Asus). With either of them in the computer there is no output from either the card or the Intel Graphics 4000 - DVI or HDMI

Both cards were fine until I disabled the HD 7750 in Device Manager at Intel's suggestion. (They wanted to know if the card was interfering with Widi) The Widi problem is now fixed and I want to get one of the cards working again

(Win7pro64, i5-3570k, GA-Z77N-WIFI)

21-02-2015, 03:54 PM
So how do you know the widi is fixed if there is no graphics output.

21-02-2015, 04:10 PM
if I don't have a card installed the intel Graphics 4000 works fine

21-02-2015, 04:46 PM
Is it possible that disabling the GPU in windows confused the motherboard BIOS and disabled the PCI-E port on the board? Check the BIOS??

21-02-2015, 06:18 PM
Or you could try disabling the intel graphics in BIOS, forcing windows(hopefully) to use the only graphics card available. If you lose all output resetting the BIOS might be need though.

Alternatively there is a way to see hidden devices in device manager, google should know it :) Then you could either enable it again or delete it so windows will redetect it.

21-02-2015, 07:22 PM
well I can't see the BIOS screen

When I press Del the computer hangs. I presume this means I have entered the BIOS? But since I can't see anything I can't do anything

If I restart without pressing Del it boots straight into Windows with HDMI display - no BIOS screen visible

There's a Reset button on the back of the case - I pushed it and it shut down the computer. Had no effect on restart

22-02-2015, 09:35 AM
If you having trouble entering bios.
Disconnect all usb devices except mouse & keyboard.
Make sure they are connected directly to the rear ports, not front ports.
Don't press Dell until prompted on the screen.

22-02-2015, 08:40 PM
I did everything you said exactly (was sceptical though)

and it worked :thumbs:

I can now get into BIOS - but no problems there

One of the cables I disconnected along with the USB devices was a long HDMI cable that's terminated at a disused TV set. I'm wondering if that was causing the graphics problem? Seems my next step is to put one of the cards into the computer and give it a try

(I've also found how to get Device Manager to show non-present devices. Apparently it's WIN+PAUSE - advanced - environment - system variables - make variable name "DEVMGR_SHOW_NONPRESENT_DEVICES" - value "1" - reboot)

23-02-2015, 09:23 AM
One of the cables I disconnected along with the USB devices was a long HDMI cable that's terminated at a disused TV set.

Yep, thats the likely cause. The graphics card will be trying to send out the signal via HDMI so would ignore the other DVI/VGA connections.
You can test by plugging it back in and see what happens :)

23-02-2015, 09:54 AM
The problem seems to be solved. I put the AMD card back in and rebooted with the monitor connected to it (and nothing else connected). I got pictures :) albeit VGA quality. Also got a message saying no AMD driver. I went to device manager and the card was there :) I re-enabled it, rebooted and all is well

I'm still not 100% sure what the problem was. I plugged the unused HDMI cable back into one of the MB's outputs and it made no difference (although I haven't tried booting with it there). I would have thought the software would require handshaking before deciding something was connected. But I suppose it's possible it detects the capacitance of the cable

I hate to admit it but the problem could have been 'me'. When I was in discussion with Intel about Widi they got me to fiddle around with the Graphics 4000 software including making a particular monitor the primary display, and I got a bit confused. It is possible that I made the graphics card the primary display in which case disabling it would almost certainly cause problems.

Even worse, I am not 100% sure that I rebooted the computer with the monitor connected to the graphics card. I certainly plugged the monitor into every available output on both the MB and the card (both HDMI and DVI) but did I reboot with it connected to the card??

Perhaps if I had done that I would have got exactly what I've just done...

Anyway, my thanks to everybody :thumbs:

23-02-2015, 01:49 PM
An induced fault is always hard to find.