screen not detected on my pc

April 26, 2011 at 03:41:04
Specs: Windows 7
Hi I am fixing a pc for my friend, the problem is tha the screen is not detected and so does'nt switch on, however the same screen switches on when connected to my laptops auxillary screen port. I have tested the ram and it works, but cant do much else if i cant see anything, Oh and I have tested 2 other screens but left with the same result, nothing.
The Board is an intel desktop O2.
Can some one shed some light on my problem please.

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April 26, 2011 at 03:44:12
Likely a bad graphics card/chip in your friends PC. If nothing at all shows up on the monitor while it's hooked up to his/her machine, then see if the video card (if it is indeed on a card) has come loose from its' socket. If not, then likely the card itself is bad.

If it's an internal (on-board) chip, then it may require a new motherboard, unless you can somehow disable the onboard video and install a card (which would be difficult at best).

"Channeling the spirit of jboy..."

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April 26, 2011 at 07:02:01
What you're referring to as a screen is more properly called a monitor, an external monitor, or a standalone monitor .

Usually when you get no video when you try booting a computer there is nothing wrong with the video adapter or the monitor - something else is wrong.

If the system has both (a) video port(s) for onboard video higher upon the back of the case where most of the ports are, and (a) video port(s) on a graphics card in a slot space further down on the back of the case, in most cases the port(s) for onboard video will NOT produce video when a video card is installed in an AGP or PCI-E X16 slot.
If you have (a) video port(s) in both places, make sure you have the monitor plugged into a video port on the card in a slot space.

Some mboards have a DVI-D port for onboard video instead of a DVDI-I port - that will NOT work with a DVI to VGA gender adapter to produce video on a VGA connected monitor.

You have not described what other symptoms you may have.


Does the power led and hard drive activity led light up ?

Do you hear the fans spinning, the hard drive(s) spinning ?

Do you hear the usual one short beep from the mboard while booting, or another pattern of beeps, or no beeps at all ?

If you hear another pattern of beeps, describe what you hear .

Has anyone changed which ram is installed in the mboard just before this happened ?

(It's NOT a good idea to randomly try different ram - it may NOT be compatible with using it in the mboard, and in the worst cases of incompatibility, the mboard may not boot normally when it is installed, and the mboard may not beep at all. Usually there is NOTHING wrong with the ram that worked fine previously.)

Has this desktop computer been moved from one place to another and since then the computer will not work properly ?

Has there been a power failure event since the computer last worked properly?

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April 27, 2011 at 04:48:12
Thanks for the heads up. The power led and HDD led lights up, and the fans are spinning, but however there is no beeping at all. The port for the monitor is still firmly in place, and works off the onboard graphics from the mboard. We have a lot of lightening storms and power surges in this area, so I'm thinking that one or the other has probebly hurt the mboard, but I need to consider all possibilities though.

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Related Solutions

April 27, 2011 at 08:23:11
You may have a poor connection inside the case, a poor connection of the ram, or failing capacitors on the mboard.

The same things can be caused by a power supply while failing or by a power spike or surge
See response 1:


Failing power supplies are common and can cause your symptoms.
Check your PS.
They often partially work, fans and hard drives may spin, leds may come on, yet you may get no video and the mboard will not boot all the way.
See response 4 in this:

If you can borrow a power supply from another working computer, try connecting that.

If it is failing, you can usually replace it with any decent quality standard sized standard ATX PS with the same capacity or greater.

Standard (PS/2) power supply size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.

Don't buy an el-cheapo (in quality) PS.
See response 3 in this:

Note - I may have mentioned Coolermaster in that - I have recently found some models have only a 1 year warranty, some are known to have premature fan failures, some are known to develop failing electrolytic capacitors.

Many people have this problem after they have installed a graphics card in a mboard slot- the capacity of the existing power supply is not enough.

Your power supply must have at least the minimum capacity required to support a system with the graphics card you are using installed, or the max graphics card you might install in the future.
(Onboard video - video built into the mboard - IS NOT A CARD ! )
If that info is not in the ad for the video card, you can go to the video card maker's web site and look up the specs for the model - often under system requirements - the minimum PS wattage, and, more important, the minimum amperage the PS must supply at 12v is stated. If you don't find that, any card with the same video chipset including any letters after the model number has very similar minimum PS requirements. Some power supplies have two or more +12v ratings - in that case, add those ratings to determine the total +12v current capacity.

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April 27, 2011 at 16:37:38
Thanks Tubesandwires, I'll be sure to try another PS and see what happens. Oh and another thing, I know that onboard video is NOT A CARD!! But thanks for your help. :))

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