PC won't start - PSU/Motherboard/Power Switch?

chez · 7 Feb 2011 at 21:11

My friend's PC won't startup, so I (working in IT) go the "honour" of fixing it.

When you press the power button, nothing happens, so I immediately thought PSU.

I opened the case and plugged it in to see if the motherboard light was lighting up and it was.

Just in case there was some kind of issue with the PSU, I tried a PSU out of one of my old PCs and the same thing happened - light on the motherboard but nothing happened when pressing the power button.

I then took the power button assembly off of an old case I had and plugged only the power button cable into his motherboard, to see if the power button was the issue and still the same thing.

I'm thinking at this point that it's the motherboard.. anyone else got any ideas? Have I missed something?

Chez

Russu_cs16 · 7 Feb 2011 at 21:18

So not even fans spinning?

Because I had a similar problem...Motherboard was lit and once i press th epower button, the fans start working especially my Gfx card (at 100%)...

chez · 7 Feb 2011 at 21:18

Nope, nothing.

stevewah · 7 Feb 2011 at 21:58

i had similar problem once and it turned out to be power button new case sorted it

chez · 7 Feb 2011 at 22:05

I thought that.

Would taking the power button off of another case and plugging in ONLY the 2-pin power button cable, then pressing the button work if it was a faulty power button on the original case, because I tried that?

malcolm · 7 Feb 2011 at 22:42

chez said:
Nope, nothing.

Had this recently on my home server, pretty sure it was the motherboard, but as it was an old skt 754 system I couldn't prove it.

I assume you've tried resetting the bios, removing all the unecessary hardware, drives, plug in cards etc? Just to see if the motherboard/memory/cpu/gfx will post?

postmanfw · 8 Feb 2011 at 00:44

Use a screwdriver to short out the power switch pins on the motherboard to rule out switch problems

Test ram
Try different monitor (rare but has been know to cause non boot)
Change cmos battery (unlikely but worth the cost)

Failing that then yes it sounds like a dead motherboard

wilko49 · 8 Feb 2011 at 08:07

Is it a new machine, or have any components/peripherals been changed recently?

chez · 8 Feb 2011 at 14:19

It's an old machine.. nothing has been changed recently.

I tried shorting the 2 pins using a screwdriver.. nothing still.

Surely if the RAM was bad, it would at least turn on, even if only the fans etc?

My friend tried it with his monitor at his house - I was trying to get it to even power on with nothing connected - no monitor, keyboard mouse etc. Just a power lead going into it.

Silenced · 8 Feb 2011 at 14:31

Edit: Removed - Whoops, I need to learn to read