|Computers DO NOT start up in "power save mode". |
"The Acer Aspire X3900 is a small form factor desktop PC ...."
If you HAVE NOT changed which ram you have installed, and if you HAVE NOT been fiddling around inside the computer case before this happened, then the most likely thing is.....
Failing power supplies are common and can cause your symptoms.
Check your PS.
They often partially work, fans and hard drives may spin, leds may come on, yet you may get no video and the mboard will not boot all the way.
See response 4 in this:
If you have added a video card in a slot to this system, small form factor power supplies often have insufficient capacity to handle the current requirements of the video chipset on the card. If the power supply does not have enough capacity, the card may work anyway when you first install it, but it is being loaded to 100% of it's capacity, or nearly so, all the time the computer is running, and eventually the power supply is damaged.
Your power supply must have at least the minimum capacity required to support a system with the graphics card you are using installed, or the max graphics card you might install in the future.
(Onboard video - video built into the mboard - IS NOT A CARD ! )
If that info is not in the ad for the video card, you can go to the video card maker's web site and look up the specs for the model - often under system requirements - the minimum PS wattage, and, more important, the minimum amperage the PS must supply at 12v is stated. If you don't find that, any card with the same video chipset including any letters after the model number has very similar minimum PS requirements. Some power supplies have two or more +12v ratings - in that case, add those ratings to determine the total +12v current capacity.
In most if not all cases, the max capacity rating of the PS is an intermittent rating. It's recommended that you do not load your PS to any more that 80% of that rating if you are going to be using something that puts a constant load on it, such as playing a recent game for hours on end.
Small form factor power supplies are more likely to develop this problem - this is about capacitors on mboards, but power supplies often have the same problem. If you open up the power supply, you may find this.
Some mboards develop this problem - electrolytic capacitors were installed on them that were not properly made, and they fail eventually - the mboard manufacturer didn't know they were improperly made at the time the mboard was made.
Open up your case and 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.: