Bad MB or PSU? - Screen goes blank while PC keeps running.

[vim0314]

I built a HTPC back in April 2010, used it for couple years as a HTPC and a daily PC without any problems. Then gave the PC to my mom as a daily use computer, but I'm having some problems with it and seeing if anyone could help me out.

I power up the computer and before it gets to windows it just shuts off on it's own. I am thinking it might be a bad MB since it'll still shut off even in BIOs screen. Shutoff as in screen goes blank/flickers a little while PC keeps running. Computer will only run for 2-3 mins then screen goes blank. I've tried moving the mem sticks already and that didn't change anything.

I think it's either the MB has gone bad or the power supply isn't strong enough to power up the PC anymore. Any recommendations on what to try next or what I should try replacing first? keep in mind this is just a budget PC for youtube, news, email, etc.

I have already read thru the PERFORM THESE STEPS before posting about POST/boot/no video problems! thread.

The specs are: (built back in April 2010)
MSI S785GT-E45 AM2+
Athlon II X4 630
Patriot 4096MB PC6400 DDR2 800MHz Desktop Memory
420 Watt Power Supply (APEVIA ATX-AS420W)
Seagate Barracuda 7200.11 1.5TB HD
and some HP DVD drive.

 

[scout_03]

do you use the onboard video or a pci-e graphic card ?

 

[vim0314]

onboard video.

 

[scout_03]

try with one memory stick at the time also could you test the system with a pci-e slot or do you have another psu around that will premit to see it your is good or that is a motherboard issue

 

[vim0314]

I have already tried with just one mem stick. I don't have a pci-e vid card to test with nor a spare psu....
tried pulling the CMOS battery then replacing it but still same problem.
disconnected HDD and DVD from power supply and booted into bios, but after a min screen went blank. If the PSU is bad wouldn't it just shut down if it was being over loaded? - like completely turn off?
My monitor still detects a signal because if I was to pull the DVI cable then the monitor will display "NO SIGNAL".

 

[scout_03]

that why you have to test psu it could give power to start and not holding it sometimes components leaking that is electronic term, then if psu if good the next part will be to check motherboard and yes you will receive no signal from monitor if the video signal is cut that is normal http://en.wikipedia.org/wiki/Leakage_%28electronics%29

 

[vim0314]

ok guess I'll go out and buy a PSU to check if it's the PSU. any recommendations on budget power supplies for the components I'm running?

Sorry I could have explained better on the no signal. When I start the computer and the screen goes blank, my monitor is still detecting a signal - because when I hold the power button on the computer and power it down, then that's when the monitor displays "no signal"

 

[scout_03]

bring the psu to a local shop see if they could test it and if psu is dead you could buy one from them if the price is fair and a good quality one get something around 600 to 650 watts with a pci-e cable connector so later if you had a pci-e card you will be able to power her

 

[vim0314]

I have a frys and microcenter close by so I'll probably go to one of those stores to find a power supply. Do either of these stores offer testing of PSUs?

For some weird reason, I got the computer to load up to windows and it's been up for about 10 mins. (Have not been able to do this at all previously.)

 

[scout_03]

i dont know for these store i dont have them around where i live,since you had the system run could you check your temp also when was the last time you dus off all the fan and system it could had been shot up from overheathing

 

[vim0314]

I have the case off right now and it's not dusty in there. A little bit of dust that I have already cleaned off...
Unfortunately the screen went blank before I could get the temp software installed.

 

[scout_03]

your out of luck for now check if you could smell something around the psu and touch the psu case if it feel hot or any other part on the motherboard also the memory sticks

 

[vim0314]

I've done that and nothing felt hot. The case reads my HDD temp and that was at 37*C.

 

[scout_03]

it is not to hot for hdd ,what are the temp of the cpu and the other readings try to load this one on so it could read the voltage motherboard sensor report http://www.hwinfo.com/

 

[vim0314]

so this time when I tried to boot up the computer, screen is always blank. Nothing shows up on the monitor, not even the MB BIOs start up part... what could I try now?

 

[scout_03]

well you will have to test the psu if you have a voltmeter here are the voltage you should read http://pcsupport.about.com/od/insidethepc/a/power-supply-voltage-tolerance.htm or bring it to a shop

 

[vim0314]

Sorry I haven't replied here in a while... Replaced PSU and that didn't work so I'm pretty sure the problem is the MB. Unfortunately I can't seem to find any MB's that support AM3 with DDR2, so that would require for me to upgrade the MB and mem...
I figured I rather look for a deal on a laptop and give my mom a laptop rather than buying more components for this PC.

 

[scout_03]

newegg got this one with ddr2 memory http://www.newegg.com/Product/Product.aspx?Item=N82E16813157274