Accidentally disabled display adapter, now no signal input from boot onwards

[thevioletdivide]

Hey all, got a monitor issue that might well be something a little more complicated.

Relevant system specs: ASRock Z77 Extreme4 motherboard, XFX AMD Radeon HD 7970 video card, cheapass (but so far reliable) Chimei monitor, Windows 7 Ultimate 64-bit.

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A brief rundown of what happened today:

1. Booted PC; screen resolution was set to 640x480 for no apparent reason (possibly something Windows Update installed yesterday, but I wasn't paying attention). Normal res is 1680x1050. No other resolutions were available when I checked the display settings.

2. Tried to update display driver (because AMD popped up the reminder to do so, and I figured that might fix the weird res problem) but the resolution was so low I couldn't actually progress through the installer as the button was off-screen, and pressing Tab and Enter did nothing.

3. Had a very tired brainfart and disabled the driver; now I cannot see a damn thing on boot, not even the usual POST stuff. I just get a "No Signal Input" message and then my monitor goes on standby.

4. Tried switching monitor cable to onboard graphics and unplugged and removed video card, to no avail. (The onboard graphics may very well have been disabled beforehand; I set this system up a while ago and can't remember, but in any case I can't CHECK because I can't even get to the BIOS.) Booting the system this way resulted in a Dr. Debug error code of A2 which the internet at large assures me is something to do with IDE but may actually just mean that one drive isn't registering properly. Tried switching SATA ports for my boot SSD but it didn't help, nor did unplugging all my non-essential SATA devices.

5. Have (perhaps unwisely) tried shorting and replacing CMOS jumper (with system shutdown but PSU plugged in and still on) as well as pressing the clear CMOS button on the back of the mobo (with system up and running), to no avail.

6. Put PCI card back in and plugged every other device back in as well; booting the system this way results in no Dr. Debug error codes but my monitor is still unresponsive; I can't tell if I'm getting into BIOS when I press F1 or delete.

7. I also at some stage unplugged and replugged the monitor from both the case itself and the powerboard into which it was socketed; I had a vague recollection that that fixed a similar non-responsive monitor issue last time, but it didn't work this time.

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I'm not sure if this is a motherboard issue, a monitor one, or a graphics card one; keep in mind that the entire system was working fine yesterday, and even today (before I disabled the display adapter) the monitor itself was still working, it was just displaying with a crappy resolution. Now the system powers on but the monitor is wholly unresponsive; pressing keys to enter the BIOS may or may not be working, I can't tell when the screen is black and I don't want to experiment when I'm working blind.

Does anyone have any ideas as to how I can at least re-enable the onboard graphics (without being able to see what I'm doing) so that I can get into the BIOS and check stuff out? Or, better yet, any ideas on how to just solve the whole mess?

Many thanks in advance, this is driving me nuts!

 

[MarkW]

Power up the computer, and hold down the F8 key until you get to the Safe Mode menu. From the Safe Mode menu, select Safe Mode with Networking.

This should get you to a working desktop.

First, Click on the AMD logo below and download the latest AMD driver. Do NOT install it yet.

Now click on the DDU icon below, and download DDU, then run it. DDU will show 3 choices. Take the Clean and Exit one. When it is done, it will restart. Again go into Safe Mode with Networking.

Now install the AMD drivers. Once that is done, you should be able to restart and go to the desktop normally.

 

[thevioletdivide]

Thanks MarkW, will give that a go and report back! Appreciate the speedy response.

 

[thevioletdivide]

@MarkW -- Couldn't even get to Safe Mode, was holding down F8 for ages but the monitor still gave me "No Signal Input" and went to standby. The first time I tried this, I thought maybe that meant it was a hardware issue (somehow) so I went ahead and unplugged and reseated all the cables again. A second attempt still failed. Any other ideas?

 

[MarkW]

Are you seeing anything from the computer on the monitor at all during the boot process?

 

[thevioletdivide]

(Sorry, had to run and do an errand.) Nope, nothing at all. I know I set the system not to show splash screens on startup, but I'm not seeing anything else either. If I start with the monitor turned off and then switch it on as the system boots up, it stays on for about two seconds, says "No Signal Input", and goes to standby.

 

[MarkW]

At a minimum, you should see the video card BIOS version info, and then info from the system BIOS on how to access it. Those do not use any drivers to function. If you are not seeing at least those, then there is a problem between the video card and the monitor. It could be that the cable is not firmly attached on one end or the other, the video card could have died, come out of its slot, or something else. THe monitor may also have developed an issue.

Bottom line, you need to see at least what I said you need to see above, or you have a 0% chance of seeing anything else.

 

[thevioletdivide]

Possibly worth noting: I don't appear to have a system speaker attached. This rig has been upgraded on a component-by-component basis several times; I know there was a system speaker at one point but for the life of me I can't work out where it is now. Peering around the case, I can't see it anywhere, unless it's tucked under one of the drive cages.

That aside: I don't usually hear POST beeps anyway, so my guess is that if there IS a speaker hidden somewhere in my case (I doubt it) it's not connected.

Second aside: In the midst of my earlier testing (somewhere around steps 4 or 5 in my initial post), I pressed delete with the intention of trying to enter the BIOS, and did hear one single beep. I've no idea where from. Possibly the mobo itself has a built-in speaker.

I realise that not being able to hear the POST sequence makes this problem infinitely harder to pin down, as my system may not be POSTing at all, but I can't do anything about that as it's well past business hours (on a Sunday, anyway) and I've no spare system speaker on hand to plug into it. :\ I also at some point turned off the launch sounds/music for Windows, so I'm not sure if it's getting to the desktop or not.

 

[MarkW]

Do you have a CPU with onboard graphics?

 

[thevioletdivide]

At a minimum, you should see the video card BIOS version info, and then info from the system BIOS on how to access it. Those do not use any drivers to function. If you are not seeing at least those, then there is a problem between the video card and the monitor. It could be that the cable is not firmly attached on one end or the other, the video card could have died, come out of its slot, or something else. THe monitor may also have developed an issue.

Bottom line, you need to see at least what I said you need to see above, or you have a 0% chance of seeing anything else.

I figured as much. I was thinking that since this mobo does have onboard graphics, that might serve as a substitute to be able to further diagnose the issue, but as I said originally, I may have disabled that, too (can't tell, obviously). So is there any way I can re-enable the onboard graphics when I can't see a thing?

Also: issue still occurs even when the video card is completely removed from the case and not plugged in.

 

[thevioletdivide]

Do you have a CPU with onboard graphics?

Yes, sorry -- CPU is Intel i7-3770k.

 

[MarkW]

You switched the cable over to the video port on the motherboard?

 

[thevioletdivide]

Yes, I tried that (when the card was removed) and the issue was still occurring.

Currently the card and all cables are back as they were when the problem occurred, but I can switch it back again if you want me to do any testing.

 

[MarkW]

Then I have to believe there is a problem with either the cable or the monitor. I doubt that both the video card and the motherboard would fail on video at the same time.

 

[thevioletdivide]

Bear with me here, because it's been ages since I last messed around in the BIOS and I can't for the life of me remember what I changed except the removal of the splash screens --

Is it possible that BOTH the onboard graphics and video card can be disabled at the same time, or would the motherboard not allow that? I think when I had my brainfart earlier today, I assumed that disabling my card (through Windows) would automatically revert my system back to the integrated graphics, but clearly that didn't happen, or it broke something else. And as stated, the monitor WAS working ... until I messed with the adapter settings.

Why would a software change make hardware suddenly fail like that?

 

[thevioletdivide]

--> Keep in mind I'm not saying you're wrong, this is an old monitor and it has had various "I don't want to turn on" issues before, it's just that every previous incident was fixed by either removing/reseating cables, or reverting software changes. It's entirely possible that it really has just kicked the bucket tonight, but it seems awfully coincidental that that would occur right after I made a change through the OS.

 

[MarkW]

The BIOS is not part of this.

Follow what I am saying here. If the video card works at all, it should show its Brand and version number, plus its BIOS version as the very first things to appear on your monitor when the power is turned on.

Then it will turn over control to the motherboard to continue the boot process, at that point, as long as the boot is successful, you will then see the "How to get into the system BIOS" stuff on the screen. That is the setting you changed long ago, but is not a factor in what is happening right now. All that setting does is allow the flash page to cover the "How to get into the system BIOS" text with a splash page, or to show the text. Either way, you should still boot. So that again, is not the problem.

The problem appears to be with the video cable or the monitor. The odds of your video card and the onboard video both failing at the same time are slim to none.

 

[thevioletdivide]

So ... I take it that in answer to what I asked earlier -- the onboard graphics should have picked up where the card left off, once I disabled the card in Windows? There isn't any way both the onboard graphics AND the card could be disabled simultaneously?

 

[thevioletdivide]

Sorry if that sounded irrelevant -- I'm not trying to be difficult here, just trying to get my head around how the whole thing works. Want to make sure I didn't do something stupid way back when (like disabling onboard graphics) and that be part of the problem now.

 

[MarkW]

The system is supposed to be smart enough to know that the only video source still in the system is on the CPU when the video card is removed. So even if you did that, it should see that there is no discrete video card in the system, and switch to the iGPU. And you said you already reset the BIOS anyways.

I suggest trying your monitor out on another system. With the same cable. And go from there.

 

[thevioletdivide]

Alright. I've been responding here on my partner's PC -- I've got a bad back, so moving my PC or monitor around isn't going to be easy, but I'll take a stab at stealing his monitor cable and trying it on my monitor and PC and see if that works. Shall report back soonish, hopefully (but if you have to go, thank you for all the help thus far!). If that (and his actual monitor) doesn't work, I guess I'm going shopping tomorrow!

 

[MarkW]

I will be gone for a couple of hours...

 

[thevioletdivide]

Managed to lug his monitor and cable over to my desk and voila, display.

I want to do some more granular testing (to work out if it was the monitor, the cable, or both), but while I have a working display I'm going to update those AMD display drivers. It's downloading slowly, but once that's done and I get around to my testing, I'll post back here with the final problem (in case anyone else has the same issue) and mark the thread solved.

Thank you again for the assistance, MarkW!

 

[thevioletdivide]

Well, that took longer than expected, and confused me quite a bit. Results of my testing below:

1. My PC + my monitor + my cable = no display (this was the initial problem)
2. My PC + different monitor + different cable = display!
3. My PC + different monitor + my cable =display!
4. My PC + my monitor + different cable = display!
5. My PC + my monitor + my cable = display!

Wait, what?

Apparently, despite having fully removed and re-seated both the power and DVI cables for my monitor three times ... it was the fourth time that was the charm. Not that I did it any differently than the first three times.

I'm going to go ahead and say this monitor+cable is on the way out anyway -- this no-display issue having happened at least twice before, under very different circumstances, I have to assume that there's a semi-faulty connection somewhere, which is the only logical explanation I can think of for why disconnecting/reconnecting works sometimes, but not always. Guess it really was a bizarre coincidence that it happened again today after I decided to disable my display adapter.

TL;DR -- If you have the same issue as me -- try fully unplugging your monitor (both power and DVI cables), then plugging everything back in solidly ... and do it a lot of times before turning to other (arguably more hazardous, or expensive) solutions.

Many thanks to MarkW for the suggestion that it was a monitor issue -- it pretty much was, just not the way either of us expected.

(P.S. Can a mod please mark this solved? Thanks!)