|No video is usually merely a symptom and there's nothing actually wrong with the video adapter.|
If it were the video adapter, it wouldn't work sometimes, not work other times - once it stopped working it would never work again.
"..that pc uses its built in video card .."
If it's built in it's a video adapter, a.ka. onboard video, or a graphics adapter, BUT IT'S NOT A CARD.
The mboard and cpu are usually the least likely things to fail.
It's almost something else that is the problem.
This, or the cpu overheating, are the most common causes of problems like you describe:
Failing power supplies are common and can cause your symptoms.
Check your PS.
See response 4 in this:
- There may be a poor connection inside your case somewhere.
Unplug the case/power supply.
Power off your monitor.
Open up the case by removing the left panel as seen when you're looking at the front of the case.
Check all the connections of the wiring to make sure they are all the way onto their pins and into their sockets, especially the main connector from the power supply. The wires close to the mboard going into the main power connector/socket should be more or less perpendicular to the mboard surface rather than at an angle. Make sure all cards in slots are all the way down in their slots.
Some Dell cases have a latch you must push one way rather than screws you must remove at the back of the case.
It is extremely rare for ram that worked fine in the same mboard previously to go bad, but it can develop a poor connection in it's slot(s).
See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:
The cpu may be overheating because of accumlated crap on the cpu fan and heatsink.
While you're in there, if the cpu fan/heatsink has mung (dust, lint, etc.) on it, clean it off, but DO NOT use a vaccuum cleaner to do that (they produce a tremendous amount of static electricity when running, and anything connected to them can discharge that to your components) - use canned air, or an air nozzle if you have access to an air compressor, or an artist's brush that can be used in small spaces, etc. It may be difficult to clean the top of the heatsink under the cpu fan - the most likely place to have mung on it - and the bottom side of the cpu fan blades unless you remove the fan. If you have a case fan, clean that too if it needs it.
With the cover still off, restore the AC power and make sure the cpu fan spins - if it doesn't, don't use the computer until you replace it!
If the cpu fan makes a screeching or rattling or rumbling noise, most likely to be noticed when the computer is first started up after having cooled to room temp and having sat that way for at least a few hours, the bearings in thecpu fan are failing and it'slikely the fan can no longer spin at it's full speed - replace the fan as soon as you can
This is possible but relatively rare.
Examine the mboard to see if you have bad capacitors, and/or other findable signs of mboard damage .
This was the original bad capacitor problem - has some example pictures.
History of why the exploding capacitors and which mboard makers were affected:
What to look for, mboard symptoms, example pictures:
Home page that site
- what the problem is caused by
- he says there are STILL bad capacitors on more recent mboards.
Pictures of blown capacitors, other components, power supplies, Athlon cpu's, etc.: