Is it the power supply?

[gcol]

My pc wouldn't boot up last Sunday morning, fans were spinning but no display on screen. Monitor is fine, graphics card has been checked in another pc and is fine. Anyway, I put it down to a dead motherboard and used the opportunity to upgrade a few components. Just installed a new motherboard, memory and cpu. Low and behold, I have the same problem - it won't boot and there's no display at all. The 5v case fans spin but the 12v cpu fan does not. Also, the two cd/dvd drives do not open.
Now I'm thinking that the power supply has died. In the past, whenever I've had a power supply die, it's just been dead. This one still seems to be putting out some juice. I've pulled the power plug out of the back of one of the cd/dvd drives and checked the voltages - there's 5v and 12v present. I also checked the cpu socket on the motherboard and there's 12v there too.
So I'm confused now - could the power supply be showing the correct voltage but not providing enough current?
Any suggestions?

 

[Igorian]

The quickest way to find out would be to try another PSU. It's always handy to have a spare.

Maplin do a cheap PSU tester, which allows you to test all the rails under load. I dare say you can get it cheaper online.

 

[gcol]

Thanks for replying Iggy. I'll have to go round to my parents tomorrow and pinch the psu from my dad's pc. I'm just stunned that the problem is still there after replacing mb, cpu and memory. If it's not the power supply, what could cause it not to display anything? Like I said, the graphics card and monitor are fine.

 

[disinfo]

The quickest way to find out would be to try another PSU. It's always handy to have a spare.

Maplin do a cheap PSU tester, which allows you to test all the rails under load. I dare say you can get it cheaper online.

Those testers dont really put the PSU under any significant load, I have a very similar one, but with digital display.

I generally only use them in conjunction with a big 1R power resistor on a heatsink, then you get a decent test.

 

[gcol]

UPDATE:
Just tried my dad's power supply in my pc and it starts up fine. Blo*dy computers.

 

[Deluks]

PSU is usually the weakest link in most PC's, vendors know that punters are more interested in CPU speed and hard drive size when buying a new PC than reliability of the 'boring bits'.
From personal experience, I recommend a Corsair model, which are quiet, reliable, guaranteed for 5 years and won't break the bank. About £50 - £60

 

[Trazor]

Before you buy a power supply, check on the following site, to see how much power you require.

http://www.extreme.outervision.com/psucalculatorlite.jsp

I would add 20% to your final figure.

As Deluks says, get a good quality power supply,Thermaltake also do very good ones.

 

[gcol]

Thanks chaps. I totally agree with the comments on getting a decent PSU. This is the one I went for http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=684734
Quite handy having Scan about 25 mins away.
All installed and back in action now. And very quiet too.

 

[Deluks]

Woah! Serious bit of kit! I would've thought one of the lower power models would do. Anyway, that'll last you through your next 2 or 3 upgrades.

 

[gcol]

Well I don't know about 2 or 3 upgrades - the bug*er only lasted a day. It's died. And before you ask.... yes I am sure it's the power supply.
Oh well, back to the shop tomorrow with my pis*ed off face on.

 

[Deluks]

What graphics card is in there?

 

[gcol]

Just back from the shop with a replacement power supply - same model. Seems ok so far.
Picked up another graphics card while I was there. I had a 7800GT and have replaced it with an 8800GT(so I can take advantage of DX10). Just waiting for the game Crysis to be delivered and then the fun begins.

Incidently, that means I have a decent Asus motherboard, AMD 64bit 3700 cpu, 2gig DDR400 ram and a 7800GT for sale if anyone wants to make an offer.

 

[Deluks]

Visiting a pal with pc probs later, I'll bear your stuff in mind.

Using Vista or XP? You can run Crysis in pseudo DX10 in XP, if you do the 'tweaks' In fact will probably be faster than real Dx10 due to the lower overheads of XP.

 

[gcol]

Ok no probs. Running 32 bit Vista. It was for DX10 that I got the new graphics card.
Just been on Unreal Tournamnet 3 with everything on full and it runs like a dream.

 

[Deluks]

That's your easter weekend entertainment sorted then