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Monitor doesnt work after replacing power supply

Last response: in Components
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December 19, 2008 2:16:14 PM

I recently replaced my power supply, and now my monitor doesnt work.

My kids computer lost its power supply after an outage. I replaced the supply and the computer powers up now, but the monitor I am testing with here at my office goes black when plugged in to this computer. I tried a different monitor, same results (both monitors work fine on another computer).

Is it possible the surge that took my power supply fried the graphics card as well?
December 19, 2008 2:37:23 PM

While its possible that a bad PSU could take out a graphics card, it would more likely take out the mobo first. Of course, it could have taken out both the mobo and the graphics card. As suggested, try a different graphics card that you know works, like from a second computer. If you get a picture, you know the problem. If there is still no picture, then the problem is deeper.

One other thing to do, since you replaced the PSU, is to double check that all the wiring is hooked up and in its proper place. Its happened to a lot of people, myself included, that a wire either didn't get plugged in where it belonged or was loose.
December 19, 2008 7:42:03 PM

Thanks! I am so un-computer hip I had to think for awhile to figure out what a mobo is. Got it - ugh!

When I posted in another thread they mentioned something about resetting CMOS. What is that and how would I do that?
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December 19, 2008 8:06:01 PM

There is a set of three jumpers on the motherboard that control the CMOS. You remove the jumper from two of the pins and put it across the other two pins for about 30 seconds, then put the jumper back to the original two pins. You need a diagram of the motherboard to show where the pins are, as their location varies. If you can figure out the make and model of the motherboard, you should be able to go to the company's website and find out where they are located. That said, unless you had previously overclocked the computer or otherwise altered the BIOS, resetting the CMOS probably won't help.
December 19, 2008 8:56:56 PM

With out knowing what components you have in your computer I can only make suggestions as to where your problem might be.
20pin+4pin connector on the motherboard.
Square 4pin connector on the motherboard close to the processor.
Flat 4pin connector @ your Video Card. Depending on what you have. Yours may or may not have one.
Alternate method to reset CMOS is to take out the Little round battery.
Mark up side with felt pen. Wait a few minutes, reinstall.
Try to keep in contact with the case at all times. Do not work where the floor has carpet. Static elec. can ruin some components. Avoid touching the on board (MB) chips.
Any Beeps?

Edit: Turn off and unplug computer before working on it.
December 23, 2008 4:55:41 PM

Thanks for your help so far. Sorry Im slow on the response but current weather has kept me from working on this.

1. 20pin+4pin connector on the motherboard. - check (not using +4)
2. Square 4pin connector on the motherboard close to the processor. - check
3. Flat 4pin connector @ your Video Card. - check, dont have one
4. Alternate method to reset CMOS is to take out the Little round battery.
Mark up side with felt pen. Wait a few minutes, reinstall. - check
5. Any Beeps? -same results. The unit powers on. I hear the DVD drive working, the hard drive has a normal quiet humm, and the fan on the motherboard is working. Monitor still says "no signal".

Because at one point a beter graphics card was installed, I actuay have two different monitor jacks, and neither one is working. I do not have another graphics card that will properly fit the slot my current graphics card is in to test it and can really get out to buy anther for a few days until the roads lear here.


December 23, 2008 7:44:11 PM

Jukes said:
Because at one point a beter graphics card was installed, I actuay have two different monitor jacks, and neither one is working. I do not have another graphics card that will properly fit the slot my current graphics card is in to test it and can really get out to buy anther for a few days until the roads lear here.
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Hold it, you've got me a bit confused here. Is it that you have two monitor slots (jacks) on the motherboard, or that you have had two video cards installed at some point?

OK, next thing, try testing the suspect video card in a different computer and see if it works there. If it doesn't, its probably bad. But if it does work in a different computer, then the video card is good and you have to look elsewhere. At this point though, I'd suspect that the motherboard got fried along with the power supply when the power surge came through. It may still provide power to the fans and hard drive, but not power the CPU or the video card, thus causing you to get the message that there is no signal on the monitor.

If you have a second computer, try the various components from the bad one in it; i.e., video card, ram, CPU if possible, sound card if you use one. If any part works in a second computer, it can be assumed as good. If all the detachable hardware works in the second computer, then the motherboard is probably shot.
December 24, 2008 3:30:28 PM

jovial12 said:
Also take a look at this thread:
http://www.techimo.com/forum/technical-support/220321-b...



OK, it looks like you got to the source of the problem and its fixed. A combination of a bad motherboard and incorrect ram placement in their slots. I'm glad its fixed and running. Seems like so many things are try, try, and try again with computers when they get ornery. Happy computing.
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