MOBO or PSU?

The PC I have in my living room I use as a server is playing up, I turn it on and I get nothing on the screen and the lights and fans inside pulse on and off I have swapped all of the hardware except the MOBO or the PSU, which is more likley to be screwed?

 

after 494 posts here you should know enough to post some details of said motherboard and computer.

Like you have lights and fans and perhaps the CD tray works so you have 12 volts.
That leaves the supplies of 5 volts for the boot sensor circuitry and 3 volts for the processor and memory to check.

 

Haha sorry mate.

It an old Compaq Pentium 4 1GB RAM, on XP Home with 4 HDD amounting to 1500GB, it's pretty old but we just use it as storage for the laptops to link to and to watch TV shows on.

It doesn't have an internal optical drive.

The lights and fans are staying on constant now but it isn't POSTing.

 

Is it using IGP or a Video Card? If it is a VC try to remove and reseat it and see if that fixes your display problems.

 

I have tried onboard and the graphics card and I get nothing.

 

Why do you think the memory & are still good?

Strip it down to basics

No HD, USB, CD, PCI cards, even mouse and keyboard .
Minimum memory - 1 stick for single channel, 2 sticks for dual.

You should get something on the screen.

Are there any lights on the motherboard, illuminated or not?

 

It's hard to say if it's the mobo or PSU at this point. From the sound of your post, it seems like you have more than one PC. Why not "borrow" the power supply from one of 'em and hook it up to the PC that's acting up? That will tell you right away what's going on. If this isn't a possibility for whatever reason, you can pick up a used PSU at your local used PC shop for under $20, or new basic 400w-500w unit for under $50. Even if the PSU turns out to be OK, it's always a good idea to have an extra on hand, and judging from the specs, I'd say the PC is an older one and a new PSU is probably a good idea anyway. You can also make a close visual inspection of the motherboard. Pay very close attention to the capacitors. Normal healthy capacitors look like this:

http://tbn3.google.com/images?q=tbn:l-O3uyAZWlRbFM:http://www.hardware-one.com/reviews/msi6309/images/capacitor.jpg http://www.fotosearch.com/bthumb/GLW/GLW137/gwc118050.jpg

Leaking/popped capacitors look like this:

http://tbn2.google.com/images?q=tbn:Y5WuxQTQI_nreM:http://www.op911.net/photos/story/capacitor.jpg http://tbn3.google.com/images?q=tbn:n6qnVlzrMn1XaM:http://i.ehow.com/images/GlobalPhoto/Articles/2162895/BadCapacitor01-main_Full.jpg

Sometimes bad capacitors won't actually have the crud leaking out the top as in the pics above, but if the top of the capacitor is not PERFECTLY flat, then it is failing. Even a very, very slight 'popped' top is bad news. Bad capacitors could easily cause the symptoms you describe, and they can damage other components, so replace the mobo ASAP if the capacitors are popped.

Good luck!!!!!!!!!!!!!

 

Cheers guys, it seems to be working now without all the LEDs and lights on intergrated graphics, I think I should buy a new MOBO anyway so I can run Windows 7, what kind of spec will I need?

I put a new PSU in about 2 years ago (650W).

Thanks again

Wayne