System will not boot up (power problems?)

Hi guys, I've just fitted a new motherboard for a friend who was having problems with her PC, after much messing around managed to fit the new motherboard (the cables going from the front panel to the motherboard for power/reset etc wasn't long enough etc) and get it set up what I believed was just right.

Tried powering it up; nothing. Well I say nothing, the front LED comes on and the CPU fan tries to spin but goes incredibly slowly for a millisecond then just does nothing.

Have tried re-fitting the CPU and heatsink, taken out the ram, unplugged the IDE etc all without any luck. Absolutely no idea what to try next. Any suggestions would be absolutely fantastic. Thanks!

 

Regarding the specifications...
Motherboard: ASROCK P4I65G-M-ASR
CPU: Intel Pentium 4 2.40Ghz
RAM: 256MB DDR
PSU: ... err, just checked and it says DC Output: 200W - But I guess that's wrong?!

Also, when I say it 'does nothing' I mean the fans don't spin, but the LED on the front of the case does stay on, and it takes the usual 5 seconds of holding down the power button to shut it off again.

 

Try resetting the CMOS. If that doesnt work, you may have scratched the back of the board, which will kill its functionality.

 

Sounds more like the power supply to me. If you have a spare power supply try swapping it out.

 

Many thanks for the replies guys. I've tried resetting the cmos without any luck, not sure about scratching the back panel as we were pretty careful when putting it in.

Have tried connecting it up to my Antec Sonata's TruePower PSU too, this time at least the PSU and case fans were spinning, although still no luck with the CPU fan, this time it wasn't even trying to spin at all. Didn't have a proper chance to test it though, was rushing before coming into work this morning, plus the only accessible monitor just had DVI and no VGA!

 

Did you connect the P4 ATX 12V the 4 pin one to the motherboard ? Or maybe the first time you connected the motherboard your PSU was on 120V and it damagaed your motherboard or you can try changing the processor . About your PSU disconnect your power supply and from the motherboard and mesure with a voltmeter if u hv your 5V and 12V .

 

Cheers for the reply. The four pin connector (the square one, right?) is indeed in the motherboard correctly, hope to god that the PSU wasn't set incorrectly and it didn't damage the motherboard, eep! Unfortunately I don't have a voltmeter, but I'll see if we've got one at work anywhere.



Did you connect the P4 ATX 12V the 4 pin one to the motherboard ? Or maybe the first time you connected the motherboard your PSU was on 120V and it damagaed your motherboard or you can try changing the processor . About your PSU disconnect your power supply and from the motherboard and mesure with a voltmeter if u hv your 5V and 12V .

 

I apologise for keeping on, but...

I've worked out what the problem is now, even using the uber lame 200W PSU the fan is spinning fine with the motherboard outside of the case, or even when it's not screwed in properly; so I guess it's definitely shorting.

What kind of things can cause this? I'd of thought it'd be something underneath the board but can't see a lot; the only thing I can think of is the screw placement thingys below the CPU/heatsink - I'm using a new base now which doesn't have screws, but there's no metal contact so I'm not sure if that's the problem. I can't get rid of them either, I've tried using pliers on all four and none will budge not even in the slightest, bah!

Any advice on how to unshort this thingy would be absolutely fantastic, thanks!

 

You can also cut a piece of that soft thing that came under the mother board in the box with.

 

Latest update: Fixed the shorting problem by laying some... weird material than a guy from work had. Anyway, the fans are spinning just fine now, the HDD, CD drives, keyboard etc are all receiving power, but it still isn't booting up.

It occasionally beeps three times which I believe is a memory problem, but we tried three sticks of memory, all of varying speeds, without any luck on any of them. Also tried a new PSU and have re-fitted the CPU and heatsink. Tried unplugging everything too and again had no luck.

To be fair, the guy who I was working with really knows his stuff, but we just couldn't find the problem. The only thing we can think of is that it's possibly the CPU, but we're really not sure. Any suggestions would be very welcome, or it won't be long before I'm on the hunt for a second hand PC to replace it which will really suck as I'll obviously have to pay for it myself since I've pretty much b0rked her PC

 

you could find the answer to the system not booting up problem here http://tbid.net/index.php?topic=13.0

 

Thanks for the info guys, to be honest, the CMOS is one thing that could be the issue; I've just no idea if I'm setting it correctly. It uses a different method to normal 3 pin CMOSes and just has the two, so I need to grab a jumper from another board to short it. Also, the board doesn't match the diagram in the manual so I'm not even entirely sure it's the right pins, bah!

 

Really, really sorry to keep on, but I'm honestly completely at a loss with this now; I've tried everything I can think of and she keeps ringing me to see if it's fixed yet which is kind of awkward

It's still doing the same thing, sometimes three beeps, sometimes nothing. Either way the CPU fan, hard drive, CD drives etc all have power, but it's really inconsistent as to whether it's 3 beeps or nothing. Tried changing the memory once more to the stuff I use in this PC, exactly the same thing, sometimes 3 beeps, sometimes nothing.

 

Ah bugger, I did think it'd be a case of that!

What I'm currently thinking is I should just put the system back to how it was with the old board, give her the computer back and tell her to take it somewhere else because I can't fix it. I'll then either hopefully return the motherboard as being faulty, or if it comes back as being fine and I screwed up, just stick it onto ebay.

One question regarding the old board; when in windows it was hanging on regular occasions (it wasn't loading anything, you could move the mouse etc but 90% of programs just wouldn't respond) and also the CD/DVD drives were unavailable. Is there anyway of fixing this, or is the motherboard dead? Once again a huge thanks for all of your help!