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: computer suddenly won't recognize monitor(s)


akalic
08-04-2011, 12:11 AM
hi,

I have a 4-5 year old HP computer and just yesterday when I was doing some photo editing, my computer just froze up (I thought it was just some kind of error or maybe it overheat..unlikely though imo..). So i reset my computer and soon after that, it didn't recognize my new asus 24inch monitor anymore.

so after letting it cool down for 15+ minutes, i turned it back on but it still didn't detect it (the monitor said the DVI cable is not connected--can't detect or w/e). so...this is what i tried to do:

1. i thought the dvi cable is somehow messed up, so i tried using a VGA cable and connecting it with a vga-to-dvi converter to my video card --> doesn't work still

2. maybe my gfx card is dead so i take out my video card, and plug in my vga cable from monitor to the motherboard vga port --> didn't work so i wanted to see if my mobo was fried? i took out the ram and it was beeping so i assume it still works

the monitor works on my other computer so i know it isn't the cable/monitor. so what's wrong with my computer?? if the video card is messed up, would the fan on it still be spinning? ugh..:okay: can the VGA port at the back of my computer connecting directly to the mobo be busted up?

N.V.M.
08-04-2011, 05:51 AM
what do you mean "reset"? do you mean BIOS reset, using the jumper? do that if you haven't.

as far as your memory is concerned, do you have more than one stick? try it with only one, if it still doesn't work, remove it and try it with the other stick.

Presto
08-04-2011, 07:01 AM
Even though the monitor doesn't detect, do you know if it still posts (beeps, disk activity, etc...)?

fs604
08-04-2011, 10:10 AM
Maybe it's the monitor?
Posted via RS Mobile (http://www.revscene.net/forums/announcement.php?a=228)

N.V.M.
08-04-2011, 11:05 AM
Maybe it's the monitor?
Posted via RS Mobile (http://www.revscene.net/forums/announcement.php?a=228)


read the post man. he tried it on another machine!

Cman333
08-04-2011, 11:51 AM
I had an issue with ONE of my two monitors randomly not working. Did you upgrade any drivers or install any programs recently? It might be a display driver. I ended up reformatting the OS and it works now.

Otherwise try another video card? Can buy a crappy one for cheap, if you're in Richmond I might have a spare one to give you. Nothing special. But should work.

akalic
08-04-2011, 02:49 PM
what do you mean "reset"? do you mean BIOS reset, using the jumper? do that if you haven't.

as far as your memory is concerned, do you have more than one stick? try it with only one, if it still doesn't work, remove it and try it with the other stick.

reset as in...I reset my computer by turning it off and back on. I don't understand why different number of sticks would make a difference? Reason i'm asking is because i have 4 sticks of ram totalling to 4 gbs.

Even though the monitor doesn't detect, do you know if it still posts (beeps, disk activity, etc...)?

hmm from my experience of having the computer for so long. it sounds perfectly normal to me. everything seems to be running just fine. that's why i immediately felt it was a display-related issue


I had an issue with ONE of my two monitors randomly not working. Did you upgrade any drivers or install any programs recently? It might be a display driver. I ended up reformatting the OS and it works now.

Otherwise try another video card? Can buy a crappy one for cheap, if you're in Richmond I might have a spare one to give you. Nothing special. But should work.

Yeah, i'll try putting in another video card if I can find one. I just don't understand why plugging the monitor directly into the VGA port on the mobo (without the gfx card) doesn't work? it blows my mind

N.V.M.
08-04-2011, 03:56 PM
reset as in...I reset my computer by turning it off and back on. I don't understand why different number of sticks would make a difference? Reason i'm asking is because i have 4 sticks of ram totalling to 4 gbs.





trying to help you here.

because 1 of them could be causing the problem! . if you want to ASSUME all your memory modules are not at fault,which its entirely possible they may not be, you'll never fix anything. this is a step by step process, eliminating pieces of hardware that are possible culprits for your problem.

so, if it still doesn't work after trying 1 stick of memory, ONE AT A TIME, then you move on to the next step, probably your PSU. it could even be that your video card simply died, and switching to the onboard video doesn't work because the BIOS won't "auto" detect a device because you have the BIOS set for a expansion video card, which is why clearing the CMOS or resetting the BIOS will help.

you don't know what a BIOS reset is? look it up and do it.

Presto
08-04-2011, 04:24 PM
Yeah, i'll try putting in another video card if I can find one. I just don't understand why plugging the monitor directly into the VGA port on the mobo (without the gfx card) doesn't work? it blows my mind

The onboard VGA may be disabled in the BIOS. There's a jumper you can short that will restore all the settings to factory default

In this case, the BIOS can be reset by moving the jumper over to connect the 2nd and 3rd pins:
http://hardwaretexpert.files.wordpress.com/2011/01/biosreset1.jpg

Or you can pull out the battery out for a little while.

akalic
08-05-2011, 03:00 AM
The onboard VGA may be disabled in the BIOS. There's a jumper you can short that will restore all the settings to factory default

In this case, the BIOS can be reset by moving the jumper over to connect the 2nd and 3rd pins:
http://hardwaretexpert.files.wordpress.com/2011/01/biosreset1.jpg

Or you can pull out the battery out for a little while.

I don't see the jumper on my board. Crappy HP mobos? The battery as in the little circular shiny metallic chip? A little while as in turn it on without it for awhile?

EDIT: okay I found the clr_cmos 3 pronged thing on my mobo. I moved it to the reset arrangement. turned on the comp for 10 seconds. turned it off. and reset it back to the original position. and tried using the onboard and the video card to no avail. fuuuucking ...:(

trying to help you here.

because 1 of them could be causing the problem! . if you want to ASSUME all your memory modules are not at fault,which its entirely possible they may not be, you'll never fix anything. this is a step by step process, eliminating pieces of hardware that are possible culprits for your problem.

so, if it still doesn't work after trying 1 stick of memory, ONE AT A TIME, then you move on to the next step, probably your PSU. it could even be that your video card simply died, and switching to the onboard video doesn't work because the BIOS won't "auto" detect a device because you have the BIOS set for a expansion video card, which is why clearing the CMOS or resetting the BIOS will help.

you don't know what a BIOS reset is? look it up and do it.

I tried all memory sticks one at a time. Didn't work..darn :P. so i put the video card into my other computer and it works. So the video card isn't dead.. I will look into how to BIOS reset, what does that mean? none of my files will be affected right?

Presto
08-05-2011, 07:25 AM
At this point, I'm wondering if your computer is attempting to boot at all. Even if my screen isn't on, there's evidence that the computer is still doing something. When switch it on, I'll hear the hard drives spin up, and then a beep as it goes through post. After post, I'll see the light blink like crazy for disk activity, so I know Windows is starting up. If you can't be certain your computer is performing the normal startup process (minus video), then perhaps it's a problem with the motherboard or something else, like the power supply.

gars
08-05-2011, 09:52 AM
AFAIK, clearing the CMOS is the same as resetting the bios. It basically resets the bios to the default settings.

The next easiest step will probably be testing the power supply. You can try testing it with a multi-meter - but it'll be time consuming. Most computer stores (like Mem Express) will test it for you for free with their tester. Call up their service department to check.

akalic
08-07-2011, 02:21 PM
it's kind of funny, because i actually used an antec 650W powersupply and then i replaced it with a ~300w stock PS from HP that i replaced a few years back because i stuck in a video card ..and it worked. Well it only worked after i booted it once, then it froze again when i reached windows 7 desktop for a few seconds. I have no idea why? i took out the video card too when i booted the comp with the old PS; so it's virtually the factory set up

is it because my new 24 inch asus LED monitor is taking too much power or something? or is there someething wrong now