PC won't power up

vbimport

#1

Hey

I just out of bed and tried to start my PC. I press the power button but nothing happens. No fans start up, no sound is made… nothing, it’s just like I haven’t pressed nothing.

I opened the case to see if the light is on the motherboard, if its getting power from the PSU, and it is. But like I said, nothing happens.

Anyone have any ideas what I should try?

Could it be the PSU? I’d hate to think it’s the motherboard.

Thanks upfront.


#2

Just in case it was caused by a power surge, where the power needs to be disconnected to reset it, try unplugging the power lead from the PSU for a minute, then plug it in and see if it powers up.

Next thing is to check that the power cables inside are firmly in place, especially the main one attached to the motherboard and the auxiliary power. From my experience, in a few cases where a PC would not power up, it was due to a loose cable.

Just in case anything has died with a short, try a process of elimination: Disconnect the main power lead, then the power cables from everything except the ones to the motherboard and video card (if attached), plug in the main power lead and try powering up. If it fails this time, then it’s possibly a failed PSU. On the other hand, if it powers up, then power it off, connect one item (e.g. HDD) and power up again. Repeat until you find what item is the culprit.


#3

I tried unplugging the cable for a min. It didn’t work.

I also tried unplugging the main power lead and than the power to my HDDs and DVD drives. That also didn’t work.

I looked at the power cables inside the case they all look ok, connected well.

Thing is I left my PC to work overnight. I doubt cables are loose or anything like that cause the PC has been in that position for like 5-6 months. Ironically the last time I opened it was to replace the power supply. So the PSU in my PC is like 6 months old. I’d hate to think it failed so fast.

But when I push the power button on my PC nothing happens, the fan doesn’t start up on the PSU, nothing makes any noise at all.

But like I said a little red light on the main board is on, when the main power lead is plugged in.

It was working fine yesterday. I was sitting on it at like 1.30 am, I left it overnight, I woke up at about 4 am it was dead.

If anyone thinks if It could be anything else other than the PSU please write in, cause my PC is from early 2005, and a PSU cost like 25 $. I’ll gladly spend the money if it fixes the problem cause I really depend on this PC for college.

PS: Seán thanks for the advice.


#4

Can you test the power on button with a multimeter or similar?
If not trace it back to the motherboard remove the connection and try shorting the two pins momentarily on the motherboard that the switch connects to.
If it starts up then the switch is faulty. It’s rare but I have dealt with 2 cases where this has been the problem.


#5

[QUOTE=weedougie;2506009]Can you test the power on button with a multimeter or similar?
If not trace it back to the motherboard remove the connection and try shorting the two pins momentarily on the motherboard that the switch connects to.
If it starts up then the switch is faulty. It’s rare but I have dealt with 2 cases where this has been the problem.[/QUOTE]

I found the pins, but could you tell me how do I go about shorting them?

Sorry english is not my first language, I just found out what you meant.

This reminds me of those white things i have in HDDs and DVD drives that set which is primary which secondary. Do I use one of them to short the pins?

Thanks


#6

That’s one way to try, but this needs to be done momentarily, i.e. connect & disconnect.

Another option would be to swap the wires to the reset button with wires to the power button. This way you could try pushing the reset button to see if it powers up the PC, since if the power button itself is the culprit, the reset button is still likely to be functional.


#7

If the new PSU cost $25 I would say that it is the cheap power supply. Buy a new good one and replace it.


#8

[QUOTE=Seán;2506025]
Another option would be to swap the wires to the reset button with wires to the power button.[/QUOTE]

I tried it. Didn’t work.

I also read on a troubleshooting site this:

To make absolutely sure you have a failed power supply and not a motherboard problem, disconnect the 20 pin Molex ATX power connector from the motherboard (this is at the end of a bunch of cables leading from the power supply), and very carefully short the green wire to any of the black wires using a bit of bent wire or a paperclip. Shorting pins 14 and 15 should do it. The green wire (pin 14) is ‘power-on’ and the black wires, which include pin 15, are all ‘ground’. Now stand back and switch on the mains power to the power supply unit. If the power supply fires up (fan spins) the PSU is probably OK and you have a faulty motherboard (before discarding the motherboard try the procedures outlined on the previous pages, including re-installing it. I’ve known dead motherboards spring into life when reinstalled<Link>). If nothing happens when you power up, you have a dead power supply.

But I’m afraid to try it :slight_smile:

Have I done enough to come to the conclusion that I have a failed PSU?

My last PSU failed 6 months ago after almost 5 years of use. But it didn’t fail like this. It started slowly restarting my pc, then that happened more and more. Than my PC started freezing, than the fans would start but nothing would come on.

Now just nothing happens at all.

This was a cheap non branded PSU, I only bought it because my PC is old and I only use it for typing and surfing the web. So I thought there would be no point in spending more money on it. It could turn out I was wrong :sad:

Anyone have any more ideas?
I doubt it was the power switch cause like I said the PC turned itself off during the night. I left it on, when I woke up it was off and since then I can’t power it back up.


#9

My vote would be the power supply has gone out, the cheap ones usually do go quickly.


#10

[QUOTE=bean55;2506032]My vote would be the power supply has gone out, the cheap ones usually do go quickly.[/QUOTE]

The way NaMeK is describing, is the same way a couple of el cheapo PSUs I had went :iagree:

So PSU failure was my immediate thought, too.

@NaMeK - any chance you can try the PSU in another (known working) PC? Or a friend/family member would let you try the PSU in their machine?

You could always buy a new, better PSU, and ask the retailer it can be returned if that isn’t the problem. They may say yes. :slight_smile:


#11

NaMeK, what country are you in? we can help you select a better one.


#12

I’m from Macedonia. Any way thanks for the offer but it’s not the PSU.

I got a new one today, I put it in. Same thing. The light on the motherboard comes on, yet when I push the power button nothing happens. The fan in the PSU doesn’t turn, nothing.

I changed the wall socket, the power cable, still nothing.

Anyone have any idea?


#13

Have you tried the power switch at the rear of the computer? I had a 5 year old Asus system failed to power on as it should with the power button in the front and had to power it on with the rear power switch. This may not be the case for yours, but it won’t hurt to try it.


#14

[QUOTE=bevills1;2506515]Have you tried the power switch at the rear of the computer? I had a 5 year old Asus system failed to power on as it should with the power button in the front and had to power it on with the rear power switch. This may not be the case for yours, but it won’t hurt to try it.[/QUOTE]

I don’t think I have one. I’ve never seen one. The old PSU had a power button on the back, but the new ones don’t.

Only think I can think of is that it must be motherboard.

I don’t know, if any one has any ideas any help would be appreciated. Thanks.


#15

I just found out what the problem was.

It was the network card.

I removed everything and than put it one by one till I found out what the problem was.

I removed the Network card, and put it in 3 time in different slots. Every time I put it in the PC wouldn’t start at all.
I don’t understand why. But that seams to be the problem.

I spent 25$ on a new PSU for nothing but what the heck you can’t win them all.

Thanks for the help guys.


#16

It’s always handy to have a spare PSU. I keep a spare one myself just in case.

Sorry, I forgot to mention in the process of elimination above to also remove all cards but the graphics. While I’ve not encountered a faulty network card preventing a PC from booting, I’ve already seen one case where faulty 56k modem prevented a PC from powering up.


#17

With most Mobo’s coming with networking built on I forgot about that :doh:

Glad to hear you got it fixed :smiley: