Strange problem: monitor not getting signal sometimes


Ive had a look around for people posting the same problem, but cant seem to find anything so...

When I first try and turn on my computer sometimes my monitor will not pick up a signal. Repeatedly turning both the monitor and computer on and off will eventually get it to work. Sometimes it will work the first time I try, sometimes the second, but sometimes it can take 10 or even 20 attempts before it finally works which, believe me, started to get annoying after the first week or so.

The problem only appears at startup. Restarting the PC from windows or letting it go to and return from standby never brings up the issue - once it has a signal it is absolutely fine and there dont appear to be any other problems once the computer is on (RAM, VGA card, CPU all seem to display and run properly).

There is one other detail though. One of the case fans wont always start. It just sits there... until you give it a little nudge and then it runs fine. The other two dont have this problem, its just the one that doesnt like to start by itself.

Ive had the computer (self-built so no warranty) for two years and the problem cropped up about a month ago and has kept happening since. Im finally getting sick of it now. It didnt happen after any driver updates so that cant be the problem either, which leads me to believe its hardware over software.

Ive tried another monitor and another cable so neither of these are to blame. Unfortunately I dont have any other spare components to try to narrow down the problem to a specific piece of hardware.

Anybody have any ideas?


24" DMQ Monitor
Gigabyte GA-965P-DS3
C2D E6300
Connect3D X1800XT
Hiper Type M 530W
56 answers Last reply
More about strange problem monitor signal sometimes
  1. Does your case have a little speaker build in that beeps when your system has succesfully completed the POST. If it does, do you hear the beep when the problem with the monitor occurs?

    The problem with the fan could be no problem at all. Do you have enabled fan speed control in your bios? If you did it could be that the voltage the fan gets is to low to get it started. So if you give it a slight push, does it run at normal speed or very slow?
  2. Its an Antec P180. I dont recall there having ever been any beeps. There certainly isnt any now.

    The BIOS fan speed control is set to AUTO. And once the fan is pushed it runs at the speed it should.
  3. Too bad. If the problem happens, does the computer go on with booting to windows? Do you hear the hard drive working while loading windows or if you have a dvd drive or floppy do you hear them making sounds when searching for a bootable device in it? This means your system passed the post.

    Btw: do not forget to enable the option in your bios to 'halt on any errors' if you have it !!!
  4. Ok, just tried it. What appears to happen is the HDDs appear to be working, then after a minute the thing restarts itself and then stops. Upon then getting the monitor to display the next time startup happens the Windows recovery screen comes up and when getting to Windows the "Windows has recovered from an unexpected shutdown" thing appears.

    Problem Event Name: BlueScreen
  5. As soon as you switch on your PSU, the HDD's will start to run. This always happens, even if you don't even have a mobo in your PC. Do you hear the drives making that scratching sound for some time so you know they're loading something big (your OS). And how about the DVD drives. If your PC starts up fine, you should hear them search for a bootable device. Are they doing that too when you have the problem?
  6. And after getting the dump file open:

    Probably caused by : dxgkrnl.sys ( dxgkrnl+15b60 )
  7. What do you mean by that?
  8. I put the DVD drive as the primary bootup device and I *think* it tries to boot from it. The light comes on at the time it should be trying but it doesnt really make much of a noise (But it doesnt make much of a noise when the monitor is working and I can see it definitely trying anyway).
  9. "What do you mean by that?"

    I meant the dump file (In c:\windows\minidump) created by Windows following the recovery from unexpected shutdown. The file contains a lot of useless stuff about the debugger not using the correct symbols (Which apparently is always meant to be there by the looks of it). Then at the bottom is has the line "Probably caused by : dxgkrnl.sys ( dxgkrnl+15b60 )" which I assume is meant to be the reason for Windows not starting and forcing a restart.
  10. Allright, probably your system can get past the POST, but still I have one question. The DVD drive LED will mostly light twice: first when you have just turned on the PC because the DVD drive gets power and second when it tries to find a bootable device. Are you sure it burns for the second time WHEN AND ONLY WHEN you have no signal on your monitor.
  11. Im pretty sure it lit up twice, yeah. Trying to check again now but the monitor is being awkward and turning on every time at the moment (It does this for some reason. Seems to have to be turned off for a fair bit to go back to not showing).

    Ill shove it off for 10 minutes or so and let you know for definite though.
  12. Alright, I'll hear from you in ten minutes then. I still have another question: most mobo's show some info on the screen after they have completed the post. Mostly it's a page with info like what bios version have or what devices are connected to the mobo and at which ports. On the bottom of that page you will mostly see "Press DEL to enter Setup". Sometimes you don't get a page with text but just a picture of a feature of your mobo.
    Did you get such an image WHEN YOUR MONITOR STILL WORKED PROPERLY?

    Btw: for the problem with the fan, try connecting another one to the same plug on you mobo, or do you power it directly from the PSU?
  13. Ok, the DVD drive definitely tries to read when the monitor isnt working.

    And yeah, the BIOS info always shows up.

    Oh, and the fan is connected directly to the PSU.
  14. So you are telling me that there is no problem with the monitor when you are not in windows yet? The PC posts perfectly, after that you get the bios info screen and when the system attempts to boot up Windows your monitor suddenly dies? Is that exactly what happens?
  15. Oops. Sorry, what I meant was the BIOS info always shows up when the monitor is working correctly. <_<

    But the PC does indeed appear to post when the monitor isnt working, but when Windows tries to load (And it must try otherwise Windows shouldnt know there was a problem?) something goes wrong and the thing resets itself.
  16. I'm sorry i'm asking so much, but the situation is not completely clear to me.
    are you saying there are two different situations?
    #1 (good): Your system posts, you get the bios info screen on the monitor, windows boots properly and the whole system in running flawlessly. You can reboot it as much as you want, it will always keep running as it should.
    #2 (bad): Your system posts, you do not see the bios info on the monitor, windows is corrupted while booting up and the system resets itself. You can say not seeing the bios info screen in an omen to tell you windows will crash.
    Have I got everything right?
  17. Its ok, I appreciate the help.

    #1 is right.
    #2 - I cant see the bios info because I cant see anything at all because the monitor has no signal. But yeah, thats right.
  18. This is very weird. I think it's problem in your PC's subsystem, this means the bios. There are two main bioses in your PC, one on the mobo and one on the gfx. I would start with the first. Reset all your settings by removing the battery on your motherboard for about a minute. Do not forget to turn off the power to your PC completely. If this doesn't work, try flashing the bios to the newest version. You can download it on the site of your mobo's manufacturer. Beware bios flashing is the fastest and the easiest way to f**k your mobo up. Read the section in your mobo manual about flashing over and over again before starting with it. If this doesn't solve the problem, it could be the video bios. You can flash that one too, but I have never done it in my life so I cannot help you on it. If I had a problem with it, I would return the card to the store where I bought it. Maybe you should do that too and they can check whether your card works or not.
    But before starting with all what I said, just check your gfx is inserted well in in the PCIe slot and the additional power cable is connected well.
    If none of this would work I would start to think something is wrong with your mobo. Because problems already show up in the bios (at this moment your PC doesn't even know there is an OS like windows installed on it) I would doubt they are caused by Windows itself. I think the bios or gfx is causing problems for Windows.
    Anyway, follow the steps in the order I mentioned them and I hope it works. Good luck :)
  19. Ok, Ill give it a try. Thanks for the help.
  20. Small question. Are you overclocking something?
  21. Remember, do not forget to turn off the power to your PC completely when remove the battery !!!!
  22. I see this so often around here, if you have "no signal" to your monitor, 99% of the time means your PC is simply not posting. Many people think that "no signal" means there is something wrong with their monitor, or video card. This is usually NOT the case and the problem lies elsewhere.
    Why is it not posting?
    Could be a lot of things, but even if fans spin, drive lights come on and off, etc that doesn't mean anything. They will do that simply because they are connected directly the power supply, and when you hit the button, you are turning them on as well.
    A few things I would try or do right off.....
    Reseat everything, especially your memory.
    Try upping the voltage to your memory slightly.
    Could be your PSU is simply starting to weaken.
  23. Have you read my post on the DVD drive? When it is in the boot sequence (like in his bios) it will search for a bootable CD/DVD. Searching for bootable device ALWAYS happens AFTER the POST. Why would that DVD drive light up otherwise for a second time?
  24. Yes Nils I have read your post.
    While your opinions and steps to troubleshoot this problem are well founded and excellant advice, I also have my opinions. And as I said, just because the DVD lights come on at startup, or even again more than once does not always mean the PC has past the initial POST sequence.
  25. Sorry for my agressive reply. You can be right but I can be right too. I just wanted to know if his system could post and because it has no speaker I tried to find out whether it could start the boot sequence or not. Sorry again.
    Let's see what Thriftweed comes up with.
  26. I have same problem as the OP. My PC usually POSTs even when I can't see it (I can hear the Windows welcome music play). Occasionally it doesn't post. I have dual boot into XP or Vista. Happens with both OS's. 1st boot priority in BIOS is HDD. Symptoms occur after flashing new MB bios and GPU bios.

    I've learned to turn off the monitor during boot sequence. Turn it back on once the lights on the KB flash. 90% of the time this works.

    PC performs perfectly except for this.

  27. So those problems showed up with you after you had flashed your GFX and mobo?
  28. Well I tried removing the battery to reset the BIOS (And it did definitely reset - the date and boot priorities changed), removing all the components and cables and reinserting them, and even dusted the whole lot just for good measure. No change though.

    Nothing is overclocked. My CPU used to be, but turning the computer on and off all the time seemed to make my motherboard decide to unoverclock it, and I couldnt be bothered to overclock the thing every time I put my computer on.
  29. Try updating your bios. It could solve your overclocking problem too.
  30. Just tried several times using @Bios (From the Gigabyte website). And it gets to 100% every time before telling me the flash has failed.
  31. I'm not familiar with Gigabytes boards. Is @BIOS a utility to flash the bios from the Windows environment?
    The fact it fails every time could be the cause of your original problem. There could be a malfunction on the chip containing the bios. Try another version of it maybe and are you sure you have downloaded a version specific for your mobo? Maybe try another version of @BIOS. Anyhow, do NOT reboot until you get a decent flash done.
  32. Yeah, @Bios lets you flash through Windows. I used its option to auto-detect and obtain the right BIOS upgrade.... so its definitely trying to flash the right one.

    Ill download a different version and try again.
  33. Ok, tried doing it manually with another BIOS version and it still didnt work.

    Interestingly it lets me save the currently flashed BIOS to file fine.
  34. Don't use any AUTO settings. Just go to the Gigabytes site and get newest bios for your motherboard. Then select the option 'Update from File' or something like that.
  35. Yeah, thats what I just tried. Same problem.
  36. Ah, I looked for BIOS downloads for your motherboard and ended up at this page:
    At the top you can choose from three revisions of it. You need to check out which revision you have (mostly written on the mobo itself) and get the right one. Because your PC is 2 years old, you probably won't have the latest revision so make sure you know which it is.
  37. And always make sure to clear the cmos every time you flash. Probably in @BIOS you will have an option like 'Clear CMOS after flash' or so. Select it.
  38. Fairly sure mine is the original because I got it as soon as it came out. Gave the 2.0 revision a go anyway (Because lets face it, you cant break whats already broken <_<) and it still failed.

    Theres no Clear CMOS option... theres a "Clear DMI data Pool" option though. Is that the same thing?
  39. So you have already tried 1.0 and 2.0? Try 3.3
    The only thing that can get broken is the chip itself. If a flash fails, you can always retry to get right.
    Btw: use a program like CPU-Z. It can see what your current bios version is. Try another flash and see if the version changes.
  40. Just tried to get a 3.3 BIOS... and realized that the BIOSes for all three revisions are identical (They all link to the same download files).

    CPU-Z shows the BIOS version as being F5... which is what it was before I tried flashing.
  41. I found out that your CPU is supported since version F11. Probably it will still crash. Are you using version 2.02 of @BIOS?

    Maybe read this:
  42. Close all other programs and also background programs.
  43. Ive tried everything from 8 to 12 now. None work. <_<

    Read that already. I did exactly as it said.

    Could just be that the motherboard was already messed up and was the cause of the original problem anyway.
  44. And have now tried it after closing every process I knew wasnt required. No change.
  45. Yes, unfortunately I think there is indeed a hardware problem in your motherboard causing the bios chip fail. If you still have the CD/DVD that came with your motherboard you can use the @BIOS utility present on that one, perhaps older versions work better.
    But how does this program actually work? I only know ASUS Update which is something similar. That one first deletes the chip, then rewrites it and finally checks it for errors. It also shows the progress of each of these three processes. Does @BIOS work like that too?
    Don't forget what I said about clearing the cmos after flashing. @BIOS should be capable of doing that.
    What does it say exactly when the error occurs?
  46. All it has is a single percentage bar. You choose the BIOS to update with. It asks you if you want to update. Then the bar fills to 100% and at the end of that the error message appears - "Flash BIOS failed !".

    Given that the bar only takes literally 5 seconds to get to 100% I dont think it bothers to delete first. And theres no option to clear the cmos or anything there.

    Apparently my motherboard has some "Q-Flash" thing in the BIOS which may or may not have a backup BIOS (I dont know if I ever backed my BIOS up or not. I probably didnt, but you never know.). The question though is whether or not Ill actually get as far as that if I reset my PC and my BIOS is dead.
  47. First try with the older version for @BIOS if you still have the mobo DVD. Otherwise try downloading it.
    I can't say for sure whether you will get in the bios or not after reboot. If you bios got completely messed up, you won't. But maybe @BIOS got it wrong about that error and your bios was perfectely flashed. I'm no wizard who can tell what happened inside that chip. Probably it's dammaged and there was nothing at all we could do to get your PC running like it did in the past again.
    Try an older version of @BIOS, why not the oldest (as you got the mobo so early). First uninstall the current version properly. If that does not help it's up to you to decide whether you want to try Q-Flash and reboot.
  48. Tried earlier versions. Its just not happening. And no idea where the DVD is.

    Im not keeping my computer turned on for the rest of my life either so I may as well see what happens when I reset. :p

    Thanks for the help with stuff.

    Ill be back! Possibly in a week with a new motherboard, but none the less... <_<
  49. Sorry I could not help you more. I'm really sorry. I hope you do not blame me for messing up your motherboard.
    But if it would boot again, let me know.
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