|"RAM has not been changed. "|
It may have not been changed by you but it could have been changed by someone else.
Ram that is incompatible with using it in the mboard can cause no beep, the mboard will not fully boot.
However, in that case, the leds would still light up, fans and drives would still spin, if nothing else were wrong.
"None of the LEDs are working....niether hard drive activity or power indicator. There is no POST beep."
The most likely thing is the power supply has failed.
- if you live in a location such as in the UK, there may be a fuse in a compartment in the plug end of the power cord to the power supply that has blown.
- if the power supply has a power switch on it, which is usually black, try it in both positions - someone may have switched that off.
- don't mess with the recessed 110/220 voltage slide switch, which is usually red - that must be set all the way to one side or the other, to the standard AC voltage used where you are located.
Failing or dead 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 can borrow a power supply from another working computer, try connecting that.
If it is failing, you can usually replace it with any decent quality standard sized standard ATX PS with the same capacity or greater.
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 (in quality) PS.
See response 3 in this:
Note - I may have mentioned Coolermaster in that - I have recently found some models have only a 1 year warranty, some are known to have premature fan failures.
"Board or CPU? It has an AMD Athlon 64 x2 5600+ CPU."
Improperly made electrolytic capacitors on the mboard eventually fail and could cause your symptoms.
Sometimes the only indication of that is the top of the capacitor is no longer flat.
If the capacitors look fine on the mboard, it's extremely unlikely there is anything wrong with the mboard and/or the cpu, unless it has been damaged while the power supply was failing which is a definite possibilty, or it has been damaged by power spikes or power surges produced during a power failure event and/or by a lightning strike.
It's unlikely the CPU is damaged otherwise even if it's fan no longer works, because nearly all modern mboards will shut off the mboard before the CPU is actually damaged if no rpm is detected from the CPU fan or if the CPU temp exceeds a certain temp.