Graphics Card failure....again!

Hello Major geeks

I am trying to fix my brother's computer. A few years ago the screen started to show coloured lines down it after a short time being switched on. I worked out it was his graphics card that was faulty, and when i replaced it with an identical one, it worked as it should again.

Unfortunately the same thing has happened again, however i think it's odd that it would be the graphics card again? How often do they go wrong? is there some other underlying fault that is causing them to degrade and break, too many amps going to the slot on the motherboard perhaps?

As a side issue the computer is also not letting me start up into normal mode since he handed it over to me to fix! It keeps taking me through the repair screens, but is unable to get things working again, just rebooting to the same screen offering normal windows startup or repair. I have also tried going to restore points in the past but with no luck. I am able to get into safe mode with networking etc through advanced boot screen

The machine is as follows

nvidia Geforce 8400GS

duel core E6550@2.3GHz, 3GB RAM,

32bit windows 7 OS (upgraded from windows vista home premium)

My plan at the moment is to remove both the HD and graphics card, replace the graphics card, back up his docs from the HD using one of my desktop caddy's and then reinstall windows 7 fresh, and transfer important dosc back over.

Any comments suggestions gratefully received :wave

Richard

 

You are talking years apart so I would lean towards a coincidence more than anything else.

But... some other underlying fault? Maybe. You need consider two things; heat and power.

With heat, it is important to understand it is the case's responsibility to ensure the innards have an adequate supply of cool air flowing through the case. So you should inspect the case interior and ensure the existing case fans are spinning and/or consider adding an additional case fan. Proper "cable management" can help too - that is, routing and tying back cables so they minimize their impact on that desired front-to-back flow of cool air through the case. Also, it is CRITICAL to ensure the case interior is kept free of heat trapping dust, and that of course, is a user responsibility. I generally recommend inspecting case interiors once a month, and cleaning when necessary. Sadly, many computer interiors are neglected - often for years, until they break.

Power does not work that way. The power supply delivers what is demanded of it. The power supply does not "push" what it can deliver. That is, if the computer (motherboard, CPU, RAM, graphics, drives, etc.) require 300 watts, the PSU will deliver 300W regardless if the PSU is a 500W PSU or a 1000W PSU. And the PSU will pull from the all 300W (plus another 15 - 30% depending on PSU efficiency), again, regardless the rated PSU power capability.

A failing, or super cheap out-of-tolerance, or underrated PSU can, however deliver "dirty" and/or unstable power, and that can put a strain on the components it is powering. Sadly, many computers come with cheap PSUs that are barely adequate from the start when new. And then users add RAM or another drive, or bigger graphics solution and that really taxes the PSU. Then ALL PSUs weaken as they age. So it may be time to consider a new PSU and if the case, make sure it is a good one, one that is 80 PLUS certified. I prefer Corsair and Antec PSUs.

Too much current results (as dictated by the Laws of Physics, specifically, "Ohm's Law) when resistance goes down. So there would have to be a "short" somewhere for that to happen and with digital electronics, that typically results in complete and immediate failure of the circuit. Not something that happens over a period of years.

 

Thanks for the reply

Yes i think unfortunate coincidence also. The fans all spin, and i used a jostick, which showed good airflow through the case. Internal power cables all have cable ties, but the usb cables don't, so i will arrange them better. Dust wise it wasn't as bad as i've seen, but gave it a good clean anyway.

I have removed the gfx card, and reinstalled windows using the on-board chip with no problems, so will just need to put the new card in when it arrives.

Thanks for the psu explanation. Replacement will be dictated by price i think. How do i determine what psu i have currently? i can't see any markings/stickers on it, and doesn't appear to be listed within device manager?

Thanks

 

That's typically where folks make a mistake. The PSU is one of, if not THE most critical device in your computer to ensure stable operation. Cutting corners to save the budget by getting a cheap PSU is like buying a fancy new car then filling it up with cheap, watered down gas from the corner tobacco hut. An engine can miss a beat and keep on running. But not high-speed digital electronics.

"Investing" in a quality PSU will ensure longer, trouble free life for everything it powers. See my canned text below for sizing and selecting a good PSU.

PSU's don't "communicate" with the motherboard or operating system. There are only power connections - no data connections (or drivers). So you cannot find any information about the PSU in Device Manager. At best, you might be able to see the DC voltages but you will not be able to determine wattage or how clean or stable it is. All PSUs "should" have a label by law. Some times the label is on a hidden side of the PSU and the only way to see it is to pull or un-mount the PSU from the case.

IF that is the original PSU, and no hardware has been added to the computer since new, it "should" be of adequate size.