help! cmos error? computer starts but shuts off!

[.insignia.]

hello, im having troubles with my desktop computer, it's done this before but ive managed to get it up and running somehow, anyhow heres what happened, i got the computer removed from my room for 2.5 week's when i got put it back and powered it up it didnt turn on, only a red light for a split second, and the cpu fan would spool up then shutoff. The psu fans remained on however for 2 minutes (cooling system).

i flipped the psu power switch off, turned it back to on. and left the computer for 12 hours, when i came back to it it started up perfectly, it said it had some error's but went to the start menu "start window's regularly, most recent best config's , safe mode" etc i clicked most recent that worked and it loaded up then crashed. tried pressing the power button and it wouldnt even flicker or spool the cpu fan. if i switch the powerbox off and back on and leave it for a period of time it will continue to do this. I tried to go to bios and change the 3 sources of start up, the first was ROM wich I dont even have? 2nd was seagate 9392848485-394 hardrive, and third was my cd/dvd reader cdrom... then before i could change to hardrive to be used first on startup it shut off. and i have to wait around 20 minutes to retry I dont realy know alot about computer's but heres some specs.

the computers about 4-5 years old with minor upgrades.
enermax 375W EG375P-VE atx 2.0 psu (was high end when i bought it)

intel 3.0ghz w hyperthreading
asus? p5pe-vm motherboard
seagate barricuda 7200rpm 500gig hardrive.
sound blaster live! sound card (very old but works)
and 2 samsung ddr 1gb ram sticks pc3200
ati x1650 pro agp 512mb ddr3

The computer worked great before i stored it in an none heated (but roofed) addition, the tower was wrapped in a black garbage bag and was not dropped or hit. 2.5 week's later its not working!! please help anything would be greatly appreciated!

btw, the computer use to try to do this when it was shut it off without warning, but i always managed to get it up and running by removing the cmos battery. now even removing and installing that doesnt help my situation. thanks for your time.

 

[linkin]

I think your PSU is toast unfortunately... If you get another one get something like a Corsair, PC Power & Cooling, Seasonic, Thermaltake and stuff like that.

For the sake of future-proofing if you upgrade your PSU, get something above 500 watts.

 

[The_Other_One]

I never really thought Enermax were very "high end" power supplies. That one doesn't look terrible, but certainly not the best. Regardless, I too agree the PSU is gone. Should be an easy enough fix, just fine a nice one with plenty of amps on the 12v rails

 

[jsmart7]

I think the fan has collected a lot of dust, enough dust to make it stop working. That is the reason, that your fan is stopping increasing the machine's heat, and thus the machine is shutting down. Just take a clean cloth and then clean all the dust from the back of the CPU. You may have to open the case too, but don't be afraid, this is not going to damage your machine anyhow.

 

[StrangleHold]

I think the fan has collected a lot of dust, enough dust to make it stop working. That is the reason, that your fan is stopping increasing the machine's heat, and thus the machine is shutting down.

Where do you see enough dust in the photo to make the fan stop working?

Just take a clean cloth and then clean all the dust from the back of the CPU.

You dont clean a heatsink with a cloth. How do you get between the fins with a cloth?

You may have to open the case too, but don't be afraid, this is not going to damage your machine anyhow.

Seems he has already opened the case (hence photo above)