Losing Display when I plug anything into desktop.

I have recently developed a problem with my new desktop build. It has been up and running beautifully for approx 8-9 months. About 2 months ago, I began to lose my display at seemingly random moments. The rest of the computer seems to be working fine when this happens, because the audio is still running and I can still control events (eg. can still hear gun firing in a game when I click mouse button). I have discovered that this is not a random occurrence and it in fact happens whenever I plug a device into the tower. This could be either a USB device like an iPod, or the speaker and mic cables for my headset. This happens almost without fail each time I try to plug something in. I have been sometimes able to bring my display back by simply switching the DVI connector from one port to another on my video card, but this is hit-or-miss. I have contacted the support for my video card, PSU, and mobo. Each has given me a different scenario. Apparently, it is either a bad 12v rail on my PSU, or a short happening somewhere in the tower wiring. I am going to attempt to bench test the machine to see if it happens outside of the tower. My questions are:
If the problem is able to be reproduced outside of the tower, then is the issue with my mobo? Also, what would be the best way to check my PSU? (the manufacturer's support is email based, and not very helpful) Finally, are there any other suggestions that may have been overlooked?
Any help I could get with this issue would be greatly appreciated.
At the very least I could stop pulling out what remaining hair I have left. :cry

 

This also happens whether I plug in via the USB ports in the front of the case, or directly in the back of the mobo. Happens when plugging my mic and headset cables into the soundcard as well.

 

It could be the motherboard but if me, I would want to verify the PSU is good first. Swapping in a known good PSU is probably the best way in this case. Here is my canned text on testing PSUs:

To properly and conclusively test a power supply unit (PSU), it must be tested under various realistic "loads" then analyzed for excessive ripple and other anomalies. This is done by a qualified technician using an oscilloscope or power analyzer - sophisticated (and expensive) electronic test equipment requiring special training to operate, and a basic knowledge of electronics theory to understand the results. Therefore, conclusively testing a power supply is done in properly equipped electronic repair facilities.

Fortunately, there are other options that are almost as good. I keep a FrozenCPU Ultimate PSU Tester in my tool bag when I am "in the field" and don't have a good spare power supply to swap in. While not a certain test, they are better than nothing. The advantage of this model is that it has an LCD readout of the voltage. With an actual voltage readout, you have a better chance of detecting a "failing" PSU, or one barely within specified ATX Form Factor Standard tolerances. Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed". Newegg has several testers to choose from. All these testers contain a "dummy load" to fool the PSU into thinking it is connected to a motherboard, and therefore allows the PSU to power on, if able, without being attached to a motherboard - great for testing fans, but again, it is not a true load or suitable for conclusive testing.

Note the required voltage tolerance ranges:

http://i195.photobucket.com/albums/z181/Digerati_Bill/One-Time%20Upload/PSUTolerances.jpg
NOTE: Disregard the -5VDC reading. It is no longer used.​

Swapping in a known good supply is a tried and true method of troubleshooting used for years, even by pros. If you have access to a suitably sized, spare power supply, carefully remove the suspect supply and replace it with the known good one, and see if the problem goes away.

I do not recommend using a multimeter to test power supplies. To do it properly, that is, under a realistic load, the voltages on all the pins must be measured while the PSU is attached to the motherboard and the computer powered on. This requires poking (with some considerable force) two hard and sharp, highly conductive meter probes into the main power connector, deep in the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it. It is not worth the risk considering most multimeters, like plug-in testers, do not measure, or reveal any unwanted and potentially disruptive AC components to the DC voltages.

The voltages can be checked in the BIOS Setup Menus of most motherboards but they do not reveal ripple or other anomalies either. And the Setup Menu places very little demands on system resource so, like the temperature readings found in BIOS Setup Menus, they may not reflect values obtained when the computer is processing demanding tasks.

And remember, anything that plugs into the wall can kill. Do not open the power supply's case unless you are a qualified electronics technician. There are NO user serviceable parts inside a power supply. If you do not have a tester or a suitable spare to swap in, take the PSU to a qualified technician for testing. ​

 

I agree with Digerati - sounds like a power issue.

 

Thanks for the reply guys. It has occurred to me since I posted my problem that the one thing I have not considered is also the most simple...my monitor.
I am going to hook my machine up to a different monitor to see if the problem persists. I know it seems improbable, but it is an easy test to do and should not be overlooked imo. If I am still losing display, then I plan to take my machine in to have the power supply tested. Once again, I really appreciate the input, and will update the thread with my findings and or (hope, hope) resolution.
Rawk On!!! :guitar

 

When troubleshooting video problems, trying the monitor on another machine, or a 2nd monitor on the computer is always a good idea and I guess I should have mentioned that initially. But the symptoms don't point to the monitor itself so I will be surprised if that is it. But I like surprises so do keep us posted.

 

Thanks for the input guys. I ended up resolving the problem by switching from the HDMI input to the DVI. I dont know if it was the HDMI to DVI adapter, the cable itself, or the input on the back of the monitor. At any rate, I am now using the DVI input, and have not had a repeat of the problem once.
Thanks again for all the suggestions.

 

That's interesting. It would be good to know what would happen with a different HDMI cable but, you got it working. The video content and quality is the same with DVI, so leaving it is understandable.

Thanks for the followup.