Monitor randomly loses signal and stops display

Hi, sometimes my monitor comes up saying 'no signal detected' and goes black. When this happens, I have no choice but to restart with the button on my computer. This means that I lose all data I have been managing which is quite a pain! I thought maybe my monitor was the problem so I tried a replacement but that does it too. My monitor and all leads are fine, so what can I do to stop this from happening?

Cheers, Justin

 

The next thing to investigate is the graphics adapter.

I might suspect an overheating problem. Have you opened the case and cleaned the dust out? If you have an add-in graphics "card" and it has a fan, check that the fan is spinning freely. Check all the other fans as well (including the one in the power supply).

I might wonder that it may be a power supply problem.

Check for updated drivers. Go to the manufacturer of the motherboard/system and look for chipset drivers, install those first, then updated graphics drivers.

As I said, it seems like the graphics is overheating and shutting down.

Matt

 

Yes Matt, I have seen this happen with a faulty PSU, but I would lean towards the video card overheating or malfunctioning first.

 

When and how often? Once a week? Several times a day? Immediately after boot after a full cool down, or only after it has fully warmed up? When did the problem start?

While I agree this looks heat related, I never like to move on with intermittent problems without knowing I have a good power source first. I would swap in a known good PSU to be sure. This assumes, as Matt suggested, the interior has been cleaned of heat trapping dust, all fans spin freely, and all cables have been checked to ensure securely attached.

I would also advice you don't focus entirely on the graphics card as a failing or overheated card does not normally cause the monitor to go black - but instead the image will become pixelated or frozen, or wrong colors. This might not be the card.

You might try blasting a desk fan inside the open case and see if it happens. What are your temperatures?

Tell us about the computer and card?

Inspect the motherboard for bulging or leaking electrolytic capacitors. These failed or failing capacitors are a common cause of sudden, but seemingly random system lock ups and reboots. The capacitors look like tall soda cans, many of which surround the CPU socket.

All older motherboards, and many of today's less expensive motherboards use electrolytic capacitors containing a liquid electrolyte. Failing (including flawed and/or abused/over-heated) capacitors literally bulge at the seams due to excessive internal pressures. Extreme (and very rare) cases result in a firecracker type explosion that can really stink up a room. Typically, electrolyte just oozes from the pressure relief point, which appears as a symbol or letter stamped in the top of the capacitor casing. The electrolyte can be caustic to motherboards and flesh. Look for white to dark-brown, dried liquid or foam on the tops or bottoms of the capacitors. Bulging capacitors are a sign leakage is about to occur.

A motherboard with bulging or leaky capacitors can be repaired, but often it is more cost effective in the long run to replace the motherboard.

Be sure to first power down, unplug the computer, and keep yourself discharged by touching the bare metal of the case before reaching in.

I would test your RAM using one of the following programs. Both require you to create and boot to a bootable floppy disk or CD to run the diagnostics. Using the floppy method is generally easier (and another reason to include floppy drives in new builds). However, the CD method is just as effective at detecting RAM problems. Allow the diagnostics to run for several passes or even overnight. You should have no reported errors.

Windows Memory Diagnostic - see the easy to follow instructions under Quick Start Information.
or
MemTest86+ (for more advanced users) - an excellent how-to guide is available here.​

 

Thanks for all your help, I've updated the driver for my graphics card and so far things have been O.K. I think that's all it was, but I've only been on my computer for 20 minutes so i guess it's too early to tell. I have a good feeling though, thanks everyone

 

That's great and thanks for the followup.