Computer locks up with black screen

[Phant0m444]

As the title says, one of my computers randomly(seemingly) locks up/freezes and at the same time the monitor has a black screen/loses picture. Pressing any buttons on the keyboard or clicking the mouse seems to have no effect after this happens, and the only way to recover from it that I know is to restart the computer using the button on the tower case. If I restart, the monitor is no longer blacked out and the computer functions normally for awhile until the next crash/lock-up.

I assumed this could possibly be a virus at first, so I decided to re-install Windows(Vista 64) and see if wiping the data on the hard drive would get rid of the (presumed)virus. After a fresh install of windows, the problem still occurs.... suggesting maybe this is not a virus problem?

I also thought perhaps the computer could be prematurely entering some kind of power saving/sleep mode. But I'm really not sure if this is true.... or how to fix it if it was. If the computer were in sleep mode, a quick press of the keyboard should bring it back... yet this does not work. I checked the BIOS for power saving settings and nothing seemed unusual, but I'm no expert either.

I'm also not sure if the computer actually crashes/freezes once the monitor blacks out. Since I can't see anything, and the keyboard and mouse don't seem to have any effect... I can't be sure if I merely lost the image or if the computer crashed/froze in some way.

Could this be a hardware issue? Maybe the video card is failing if the monitor blacks out randomly? I'm purely guessing here...

What could be causing this? How might I fix or diagnose the problem? Any help is welcome and appreciated.

 

[Steltek]

Please provide full system specs (i.e. CPU, motherboard, hard drive and/or SSD, DRAM, video card, power supply, etc - include model numbers if possible).

How old is the system? Have you recently opened it up and blown out the dust (especially in the CPU cooler fans, the GPU fan shroud, and the power supply fan)?

Also, have you tried to totally disable sleep mode on the computer?

 

[Phant0m444]

Please provide full system specs (i.e. CPU, motherboard, hard drive and/or SSD, DRAM, video card, power supply, etc - include model numbers if possible).

CPU: Intel Core 2 Duo E8400
mobo: Gigabyte GA-P35-DS3L
RAM: 4GB DDR... Corsair XMS
GPU: 1GB Radeon HD5450
HD: cant remember atm... its old and not an SSD
PSU: Antec Smartpower 350W
OS: Windows Vista 64
Monitor: Dell 19" LCD... several years old... cant find model #

How old is the system? Have you recently opened it up and blown out the dust (especially in the CPU cooler fans, the GPU fan shroud, and the power supply fan)?

Not exactly sure how old system is... its mostly a hodgepodge of old parts from my previous builds. The video card and PSU are the newest parts if I remember right.... about 9 months old maybe. The rest (CPU/mobo/RAM/HD) is very old.

I rarely dust... couldn't hurt I suppose. But I live in Colorado, and its been really cold lately. I doubt heat is an issue this time of year....

Also, have you tried to totally disable sleep mode on the computer?

How can I do this on Vista? Or through BIOS? I couldn't find much when I checked BIOS settings...

 

[denis280]

a Little dusting wont hurt.but i would suspect the HD

 

[VirtualLarry]

I suspect the PSU is going.

 

[C1]

Most computers (at least ones I have) show voltage levels in the BIOS (for 12 and 5 volt levels). At least look in there to determine if voltages are well within spec or instead marginal.

You could also use the pause key to halt on POST and leave the computer running (even over night). If it fails, then you know it isnt the OS (hardware issue with high confidence).

 

[mlc]

PSU would be a good place to start... Can you swap another one in from another pc to verify?

If you're plugged into a UPS, try bypassing to rule that out...

Check the EVENT VIEWER to see if there are any error messages associated with the system going blank...

 

[Phant0m444]

Sounds like most of you are suspecting the PSU or the HD. The only other PSU I have is in my gaming rig. I suppose I could transfer the PSU from it... but that would take awhile to connect and move back and forth :\.

Assuming I can find voltage readings in my BIOS... what are acceptable voltages for the 12V and 5V? I'm kind of oblivious to this stuff usually...

I really don't have a spare HD either... I don't want to transfer the one in my gaming rig and have to re-install everything.

I don't mind buying replacement hardware... I just hate to buy something I don't need. I want to be sure of what the problem is before I purchase new parts ideally....

I will post again if I figure anything out. Thanks for the suggestions so far.

 

[VirtualLarry]

what kind of cable is connection the video card to the monitor? You might try another cable of the same type, or possibly of a different type (different video card output, different monitor input).

 

[VirtualLarry]

I'm also not sure if the computer actually crashes/freezes once the monitor blacks out. Since I can't see anything, and the keyboard and mouse don't seem to have any effect... I can't be sure if I merely lost the image or if the computer crashed/froze in some way.

do you have speakers connected? Next time this happens, try pressing the power button briefly, in order to initate a soft shutdown (don't hold it down and force a hard shutdown).

If you hear the shutdown music, and it shuts down, then the computer didn't hard-lock.

Chances are, if that is the case, then the problem is with the video output somehow, either video card, cable, or monitor.

 

[Phant0m444]

Great suggestions VirtualLarry. I will investigate those as soon as I'm able.

 

[Steltek]

CPU: Intel Core 2 Duo E8400
mobo: Gigabyte GA-P35-DS3L
RAM: 4GB DDR... Corsair XMS
GPU: 1GB Radeon HD5450
HD: cant remember atm... its old and not an SSD
PSU: Antec Smartpower 350W
OS: Windows Vista 64
Monitor: Dell 19" LCD... several years old... cant find model #



Not exactly sure how old system is... its mostly a hodgepodge of old parts from my previous builds. The video card and PSU are the newest parts if I remember right.... about 9 months old maybe. The rest (CPU/mobo/RAM/HD) is very old.

I rarely dust... couldn't hurt I suppose. But I live in Colorado, and its been really cold lately. I doubt heat is an issue this time of year....



How can I do this on Vista? Or through BIOS? I couldn't find much when I checked BIOS settings...

Sleep can be problematic on some older machines. You can disable sleep mode by going in to the power applet in Control Panel. Edit the power settings and choose to never sleep (also disable hibernation as well). You may also have some sleep state options in the system BIOS. As a last resort, you can also disable power savings options on the power tabs of various system components (i.e. USB, video card, hard drives, etc) in Device Manager.