computer wont' start

[nater]

for a few months now my computer would randomly shut itself off...usually if I left it off for a few minutes it would start back up again without a problem.

about a week ago I shut the computer down and then it wouldn't turn back on the next day. The fans inside whit and the drive lights flash, but after about a second everything would just stop. The green light on the motherboard would remain on until the plug was pulled.

I just now tried a different power suppy. Initiall the fans whirred and drives started. This would last maybe 3-4 seconds, then it would all shut off. Now with this power supply all that is happening is the 1 second drive lights flashing/fan whirring like the other PS.

I've cleared the CMOS and that didn't do anything.

Any ideas?

 

[db2]

What size are the power supplies that you tried?
What are all the pieces being powered by the power supply?

 

[KB]

Just some ideas.... Verify your motherboard isn't touching your case. Did you use try power supplies with greater wattage than what you had? Is the power button on your case "stuck"? Are you using a UPS? If so try without the UPS.

 

[nater]

to respond to questions:

both power supplies are 300w (the one I had been using is an Antec, the other is a TigerPro)
I have disconnected the two optical drives and two hard drives (the storage ones, not OS) just to decrease the power load and try and get the machine started.

I'm guessing it's the power supply, motherboard, or processor, but I have no idea how to determine which is at fault. The second PSU is new but I have never used it before. I am not using a UPS, and the power button isn't stuck.

 

[db2]

Not knowing how old your system is but you have listed some of the main areas to look at.
Is heat a probelm inside your computer case?
Is there a dust buildup inside the computer case?
Have you tried to reseat the memory?

 

[montag451]

have you got a voltage tester to hand?

Check the atx connector from the psu's voltage, or the molex voltages

 

[nater]

system specs:
Tbird 1.4
Shuttle AK31
512 meg ddr
ti4200
Adaptec 29160 w/ (2) 18 gig 10k RPM IBM HDs (Os/programs are on these)
two other ide hard drives, cdrw and cdrom

I have reseated the power and data cables to everything, as well as the graphics and pci cards and memory

there isn't really a dust buildup inside the case, and the second PSU I tried is extremely clean

I do not have a voltage tester

 

[montag451]

Try taking out/disconnecting everything apart from
cpu/psu/ram

What happens?

 

[nater]

I took everything out of the case and connected only the bare necessities to the motherboard (cpu, psu, ram) I still get the same thing with both power supplies...fans whir for a second, motherboard light turns on, but nothing happens. is there any way I could tell for sure that it is the motherboard, processor, or ram?

 

[GAZZA]

Not unless you have other components to verify with.

Usually with the mobo light on that means it should be OK (no gurantee tho)

Have you tried resetting the bios ?

 

[nater]

I have reset the bios, yes

 

[mechBgon]

That may be too much load for a 300W Antec, particularly if it's an older 300W Antec (I can think of four different generations of 300W Antecs). How about a nice 350W+ Enermax

 

[montag451]

unless you can swap out cpu/ram/vga/mobo/psu, you aren't gonna be getting many more ideas i'm afraid

 

[nater]

I've thought that it might be too much for the PSU, might then again it ran ok for the last six months so I think it's odd that it won't start at all now. I decided to order some new parts from newegg (p4 3.0!, new board and PSU) so hopefully I can test what I have now to figure out what's wrong so I can sell the working parts. Oh well. Thanks for all your replies everyone