Seachicken

I originally posted this in the XP forums by mistake, so I'm reposting it here.


I have a recently build computer (assembled by a friend who has successfully assembled a number of computers before) that is not working.

When I attempt to switch my computer on, the lights come on and the fans turn, but the monitor does not display anything or even recognise that the computer is switched on. In addition, I cannot switch the computer off unless I turn the power switch off at the back. I can however restart the computer (though this doesn't seem to fix anything and there is a delay between pressing the button and the computer resetting)

I noticed that the fans all go at full blast which based on my googling suggests that the 12 volt rail is working fine but nothing is coming from the motherboard to tell them what speed to spin at. The odd thing is that every now and again, the computer will switch on and run for a long while, and the motherboard light does appear when I press the power. I'm not sure if this is anything, but there seems to be a very slight rattling buzz coming from the PSU, even when the power switch is off.

At first I thought that this was a graphics card fault because the computer will switch on all of the time when my 8800GTS graphics card is not plugged in. However, the same problem also occurs with my friend's 8600.

The PSU is a 460W Coolermaster, which many people on another forum have told me is more than sufficient.

I can't say I'm sure about this, but the computer seems to be more willing to turn on after it has been left off for several hours.

Does this sound like a faulty psu or something more serious?

Also I have been getting a lot of DRIVER_IRQL_NOT_LESS_OR_EQUAL and STOP errors lately which I assumed would be a driver fault, but I thought I'd mention it anyway just in case it is connected. It also does seem that the computer doesn't like to start up after these errors, but I really couldn't link the errors and the failure definitely (it has failed many times without a BSOD).

Thanks in advance for your help and tell me if you need any more system information.

Tumbleweed36

You may have more than one problem. First of all, a Coolermaster 460 is way underpowered for the 8800GTS, so the first thing I would try is a more powerful power supply. Do you have one that you could borrow from a friend to try in here? For this video card you need to be thinking about a 650 watt power supply from the following manufacturers:

Seasonic – Any Model
Corsair – Any Model
PC Power & Cooling – Any Model
Thermaltake – “Toughpower” Series Only
Coolermaster – “Real Power Pro” Series Only
Silverstone – Any Model

Seachicken

Interesting, on another forum where I asked about this there was a group of people who went to the point of being abusive at the idea 460w wouldn't be enough. Is the 8600 a power intensive card, because the computer wouldn't work with that either and it isn't nearly as massive.
My friend has a 500w coolermaster, but that's the best I can do short of buying a new one (which I'm more than willing to do if it fixes my problem)

Edit - In the interim, is it dangerous to run my computer underpowered until I do sort this issue out?

rhantson

To start, they are right on the power issue... you definately need to upgrade... it's always better to have more power than not enough...

As for running the PC without the proper power supply installed... DO NOT DO IT... you can do some long term damage to just about everything in the box. You may not notice the problems immediately, but it will definately shorten the lifespan of the components in the system.

dai

when you find you have posted in the wrong forum pm a mod to move it
don't start a new thread

Seachicken

Sorry, I'll bear that in mind in future.

TheShadowFl

There are a number of different voltages that come out of a computer power supply.
12v powers the drive motors.
5v powers the LED's.

So if those two voltages are present, lights will come on and fans will turn.
But there is one more voltage that seldom ever gets honorable mention and that's the -5v line. If that Minus five volt line is dead, the motherboard will NOT boot up.
In the past year, I've replaced a dozen or more PSU's and almost all of them have had the -5v missing.

I use a little PSU checker to determine whether a PSU is bad or good.
You can check a PSU with a digital volt meter too, but it's a lot harder.

For any modern day computer, I'd advise at least a 500w PSU (as a bare minimum) and then go right up from there, depending on the other hardware to be installed in the system.
That rated wattage is only the start up wattage, good for a few seconds, while the fans start up and the capacitors on the mobo are charged. The all-day running wattage can be as much as 30% less than that wattage printed on the outside of the PSU.

The more powerful and reliable supplies have multiple 5v and 12v rails.

Good Luck,
The Shadow

Seachicken

Thanks, so this would suggest that the problem is between the rated wattage and the -5v line would it? Because the computer does start up some times and when it does it runs until I encounter a BSOD. The reason I ask this (apart from out of curiosity) is if it turns out that the PSU is faulty I can either take it back for a refund or possibly credit toward a better model, I just need to be really sure it is actually the PSU that's at fault. Also, would the slight rattling buzz the PSU emits when plugged in act as good evidence for the purpose of establishing the model is faulty?

Edit- Also what are good 12 and 5 v ratings? This current one has dual 18a for the 12m 25 for the 5 and 22 for the 3.3

Seachicken

Okay I bought a new PSU and it still doesn't work.
Any ideas?

vladimirb

Hello there...
You did not provide us with full system specifications...
Did you test RAM memory????
Download MemTest86+

http://www.memtest.org/

If you have more then one stick, test them separately, one-by-one...

You said you built new PC...
All components are brand new???
Even if HDD is new, I would test it...
From manufacturers Web Site, download testing tools and test your HDD for possible bad sectors...

If you still have no display, then I would suggest you too unplug all components and leave just CPU, RAM + graphic card hooked on Motherboard...
Start PC...

You have checked graphic card on another PC???


Hope this will help you mate...
Report back please...

Seachicken

SOLVED IT, it was a RAM issue (BOTH of my sticks of RAM were faulty)

Thanks for your help all, I discovered the cause of this fault through another thread on this forum so you still get all the credit.

vladimirb

Hello there...
I am glad you have sorted things right mate...
mark this thread as solved please...