|emachines computers are well known to have el-cheapo power supplies that tend to fail more often than average, and when the power supply fails completely, they are a lot more likely than average to damage something else, often the mboard.|
If you have not been fiddling inside the computer case just before this happened and have not changed the ram installed in it, it is very likely that if you replace the power supply BEFORE it fails completely, doing that will restore your system to working again.
Unplug the cord to the computer, or otherwise switch off the AC power to it, open up the computer case, and find the label on the power supply - if the brand is BESTEC I advise you, if you find ANY indication the power supply might be in the process of failing, DO NOT trying booting the computer anymore - if the PS fails completely there is a strong likelyhood it will trash your mboard!!!!
Failing power supplies are common and can cause your symptoms.
They often partially work, fans and hard drives spin, leds come on, yet you get no video and the mboard will not boot all the way.
Check your PS.
See response 4 in this:
There's a definite possibilty you may have to replace the power supply AND the mboard.
If you can temporarily borrow a power supply from a working computer, try connecting that before you buy a power supply. If the computer still won't boot with another power supply, you can probably find a used emachines installed mboard on the web to replace it with, and that will probably get your system working again, but you may want to do something else instead.
DO NOT replace the power supply with another BESTEC one!
In most cases you can replace with a standard sized standard ATX power supply.
Standard PS/2 power supply size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.
Don't buy an el-cheapo PS.
See response 3 in this: