# Computer turns on but only black screen.



## xxpyro99 (Aug 20, 2008)

Hello. I've come to hopefully find a solution to a boot up problem I'm having with my computer. There are several factors that I'm honestly not sure will play a role or not, mainly because I'm not very understanding when it comes to computers.

The problem is that when I push the power button of my computer, it sends no signal to my screen. I can't tell if it loads anything or not either. I can think of a few things that might have some effect on this, but I'm not sure.

About three months back after cleaning my neglected tower of dust and such, it started to shut off rapidly after boot up. To inspect the problem, I had a friend look at the computer. He removed the cooling unit on the Processor revealing that my 8year old computer had next to no thermal compound. So after putting of ordering some for about three months, we had applied some about 2 days ago. The computer then booted up fine, but seemed to have an excess amount of lag. So I wiped the computer and reinstalled XP tonight. When it was booted up, it worked fine, so I went into IE to download firefox as it's my preference, then started reinstalling my drivers. First I installed my Videocard, then kept my computer booted up for my sound drivers which I got from the Compaq homesite. After doing this, I rebooted my computer. Not I wanted to get simple things such as AIM and and Java. So when i go to boot up Firefox from it's default homepage, my computer shuts down. when I go to reboot it, it doesn't start and I'm forced to unplug and plug in the tower. It continued to boot me from various sites. So after getting fed up with that, I reinstalled my Oblivion having already installed my sound and video cards. After about an hour of playing that it froze, that's when I shut down my computer manually and tried to reboot it. and it starts but doesn't send anything to my monitor. After reading a few posts on here, I took out my video card and cleaned, made sure it was connected, and retried. I still got nothing.

Is there any chance anyone could give me a hand with this all?


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## xxpyro99 (Aug 20, 2008)

Ok, so after further testing, hooking my monitor to my onboard video card gets no results either. I've tried removing my memory sticks one by one, also leading to no results. I've tried a different power supply as well, giving nothing new.


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## mack1 (Nov 27, 2007)

Hi xxpyro99 and welcome to TSF:wave:

Does everything seem to work except the monitor? 
Fans turn, keyboard blinks at start, mouse does startup blink, harddrive light flash, floppy drive grunt,etc.?

Do you get any beep codes through the speaker?

Try this, remove all the memory and do a boot. You should get a long beep code. If not, try replacing the BIOS battery.

It could be that the monitor just failed. See if you can borrow one to try.

Post back and tell how it goes.

Best regards,
Mack1


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## xxpyro99 (Aug 20, 2008)

well I know for a fact the monitor is fine, I'm not getting the Floppy "grunt" and as I've only got the one keyboard, I'll test that after I make this post. My fans all spin, we've removed the battery and reinserted it, having no replacements lying around (tho if it comes to it I'll pop the one from this tower out. Might I ask what the "harddrive light" is?


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## xxpyro99 (Aug 20, 2008)

alright, battery swap did nothing, no memory did nothing. Speakers gave out no noise either.

EDIT: Keyboard did not respond either.


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## mack1 (Nov 27, 2007)

Hi xxpyro99,

The harddrive light is normally on the front of the computer and flashes when the drive is accessed. There is also one on the CDrom drive that flashes when it is accessed. All the indicator lamps should blink at boot time. There is also a couple of LEDs on the motherboard that should light up. A red one and a green one. 

You need to find out if you are getting any activity from the CPU. If any of the lights flash, it could be an indicator that the CPU is working. 

Try unplugging things one at a time and watch for boot activity (flashing lights) after each is unplugged. Remove the video card and all other cards. Unplug the CDrom drive. Unplug the monitor. Unplug the floppy. Unplug the harddrive. You might find that one of these has shorted and keeping everything else from working. 
Remember to always tough the bare case to discharge static electricity before touching anything inside the computer.

Take another look at the CPU and its heat sink. Take it out and put it back in.

See if any of this will make a difference.

Hoping for the best,
Mack1


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## xxpyro99 (Aug 20, 2008)

Alright, I'll be sure to give these a try shortly after I get up. I've spent all night fiddling with the old thing and could use a nap before it stresses me out anymore. I believe something could have gone, everything on the computer save the videocard, hard drive, and diskdrives are stock. From a quick glance at the powered up MB, I'm seeing nothing that look as though it would give off light. I get a solid green light from my master disk drive and a blinking green light from the slave. (if that matters at all) 

I took a few pics off my phone, though I don't know if will help at all.

http://i158.photobucket.com/albums/t119/xxpyro99/0820081052.jpg
(idle after boot up)
http://i158.photobucket.com/albums/t119/xxpyro99/0820081052a.jpg
(when booted up, disk lights on, power light on, orange light? on)
http://i158.photobucket.com/albums/t119/xxpyro99/0820081054.jpg
(inside 1, above video card)
http://i158.photobucket.com/albums/t119/xxpyro99/0820081055.jpg
(inside 2, below video card)
http://i158.photobucket.com/albums/t119/xxpyro99/0820081055a.jpg
(back on tower)


I'll be back later.

Thank for the effort, Mack1


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## mack1 (Nov 27, 2007)

Hi xxpyro99,

We must be about half around the world for each other. It is just after noon here. 

I couldn't tell anything specific from the pictures. Looked like you have both a cdrom and dvd rom and each had a light on the front. Normally both those light would be off, but yours might not work that way. In any event, they should blink if the units have activity. It looked like the harddisk light might been the one toward the bottom across from the power on lamp. It was off in the picture. 

I first looked to see if I could see any deformation on the electrolytic capacitors on the motherboard. I couldn't tell from the picture, the resolution was not good enough. They are the round cylinder parts about the size of your little finger or less. The top of them is flat and sometimes have an x across that surface. A bad capacitor will often swell up at those x ends. If a power supply shorted and passed house voltage to the motherboard, it would fry the board and those capactors will often show that type damage. 

Have a nice nap and tell us how it goes tomorrow.
Best regards,
Mack1


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## xxpyro99 (Aug 20, 2008)

I removed the motherboard completely and looked for deformations and found nothing.
While it was out I also attempted to boot one object at a time again with the same results.

To recap everything I've done so far


```
Applied 2 different monitors known to work.
Booted from onboard graphics known to be functioning.
Booted from an old pci video card known to work.
Booted from No Ram, 1 stick, 1 stick opposite, 2 sticks.
Swapped Cmos batteries and booted a seperate system successfully.
Booted from alternate more powerful power supply with the correct voltage.
Removed motherboard completely from case and underwent all tests again.
Viewed motherboard for damage.
Unseated CPU, checked pins, reapplied brand new thermal paste and reseated heatsink.

I am currently unable to access post of any sort still.
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## mack1 (Nov 27, 2007)

Hi xxpyro99,

Sorry I am getting back late, the forum's notification system seems to have let us down today. Just happened to check back to see and you had posted several hours ago. 

Looks like the options are getting harder to find. It would be nice to know if the CPU was Ok and/or the mother board was Ok. In my family circle, a similar thing happened last year. My son's E-machine failed and it was obvious that the mother board had failed.(swelled capacators) The only question was was the AMD slot A type processor was Ok. I took it to a local repair shop and they checked it out for me. It tested Ok and we replaced the motherboard. That fixed the problem. 
If you have access to a usable motherboard or processor, you should be able to isolate the problem that way. 

Beyond that, I'm out of ideas at this point.
Sorry,
Mack1


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