PC Power supply problem

[paul_oshea]

Right lads PC isnt turning on. Changed the fuse in the plug, still no change computer wouldnt turn on, then changed the actual power lead and tried another one, still wouldnt turn on. The switch seems to be fine as it clicks but absoloutely nothing happens, so is this a motherboard problem or the power supply in the pc knackered? Would the fan come on if it was a motherboard problem? anything else i can check for, ive often changed hard drives, cd/dvd roms etc but never changed the power supply thingie in a pc.

[noby]

If you have some way of measuring the voltage out of the power supply, that will answer your question. Are you sure the socket is working by the way?

To change a power supply is straight forward if you're familiar with pcs. I only just changed my sister's one recently (my sister's pc that is. I don't have a robotic sister).

[paul_oshea]

noby i was getting confused there about your robotic sister

are power supplys standard as in one fits all?

The pc is plugged into a 4 plug extension lead, everything else plugged in works fine i.e. the router, speakers and monitor. The lead that went into the monitor also fits the computer so i tried that but it still didnt work.

[Dazzy]

are power supplys standard as in one fits all?

Pretty much, the cheap ones seem to last about a year in my experience, so its worth getting a good psu.

[Superhoops]

There is a small black rocker switch located directly beneath where the power lead plugs into the PC, generally marked with O and -. Make sure the switch is set with - pressed in on the On position.

[paul_oshea]

i dont see why that would have come undone superhoops....if it were ligthning would the fan still come on? i mean how do i know if the motherboard isnt just screwed and nothing to do with the power supply at all?

[noby]

i mean how do i know if the motherboard isnt just screwed and the power supply at all?

measuring the voltage out of the power supply

So, is the fan coming on? I'm confused.

[paul_oshea]

noby edited there for ye....sorry about that.

what i meant to say is, how do i know its not the motherboard that is screwed completely, would the fan come on even if the motherboard was screwed?? Therefore suggesting it wouldn't be the power supply but the motherboard that would be the problem........at the moment though nothing comes on, no life in the old dog as the man says.

[Superhoops]

noby edited there for ye....sorry about that.

what i meant to say is, how do i know its not the motherboard that is screwed completely, would the fan come on even if the motherboard was screwed?? Therefore suggesting it wouldn't be the power supply but the motherboard that would be the problem........at the moment though nothing comes on, no life in the old dog as the man says.

If the motherboard was fried and the PSU was OK, the power light would come on at the front of the PC, the fan would run but the PC would not boot up.

If nothing comes on at all there is a 95% + chance the PSU is fuc**d. It would be bad luck if both PSU and m/board went at same time.

My only other suggestion is that on most m/boards there is a small neon light (usually green or red) which lights up when the power is connected, even before you switch on the PC.

If this light comes on when you plug in the power lead, it means that the power is coming to the m/board through the PSU.

I am not sure if this light is on all m/boards, but both my PC's have an Asus m/board and it is on both of these.

Can't help after that.

[GavinZac]

if it were a motherboard problem, you would have the motherboard coming on and beeping.

i reckon its not just a motherboard problem, but a motherboard destruction. a little scratch or a little electrical shock can destroy the whole thing and make it unresponsive. did you take anti-static measures when openning the PC?

[Superhoops]

if it were a motherboard problem, you would have the motherboard coming on and beeping.

i reckon its not just a motherboard problem, but a motherboard destruction. a little scratch or a little electrical shock can destroy the whole thing and make it unresponsive. did you take anti-static measures when openning the PC?

GZ, if it was 'just' m/board destruction, would he not still be getting power to the fan if the PSU was working?

[paul_oshea]

i reckon its not just a motherboard problem, but a motherboard destruction. a little scratch or a little electrical shock can destroy the whole thing and make it unresponsive. did you take anti-static measures when openning the PC?

i didnt open it up yet. Ya hoops i thought the fan would still come on even if the motherboard was fupped.

[GavinZac]

GZ, if it was 'just' m/board destruction, would he not still be getting power to the fan if the PSU was working?

no - because the signal from the motherboard to say "im on, turn on the fan" wouldn't be received. the power button at the front goes directly to the motherboard. the BIOS/CMOS of the motherboard then instructs the CPU fan, drives etc to request power.

[paul_oshea]

the power thing goes to the motherboard but the PSU connects directly to the motherboard and thats how the motherboard gets power.

anyhow i opened it up, paid 37 sterling for a new PSU and hte light was coming on the whole time in the motherboard i just never noticed, however thats all that happens it must be fupped so im going getting another motherboard tomorrow. do motherboards come in the same size with the same sort of stuff?? im just going to get it in pc world or somewhere like that, cant be arsed waiting round. plus ye know exactly what you are getting when ye walk in etc....

[GavinZac]

the power thing goes to the motherboard but the PSU connects directly to the motherboard and thats how the motherboard gets power.

... i know, but the fan will never know to come on unless the motherboard tells it to, and the motherboard will never come on if its broken and cant get the signal from the front button

anyhow i opened it up, paid 37 sterling for a new PSU and hte light was coming on the whole time in the motherboard i just never noticed, however thats all that happens it must be fupped so im going getting another motherboard tomorrow.

told you so!

do motherboards come in the same size with the same sort of stuff?? im just going to get it in pc world or somewhere like that, cant be arsed waiting round. plus ye know exactly what you are getting when ye walk in etc....

theres ATX size which is most common and microATX or uATX as it is sometimes written (u representing the greek letter 'mew'). ATX is about the size of a laptop "keyboard", mATX about 2/3 the size of a laptop "keyboard".

[paul_oshea]

gav this this one is about the size of a normal laptop in a square shape rather than rectangle. actually its exact measurements are:

9.5 inches by 9 and3/4 inches.

does it sound like the motherboard is fupped then? i get the orange light and i get a little static sound from the motherboard and then nothing happens. if so whats a good cheap motherboard i can get from pcworld ,will i have to pay for the processor separately?

I am also assuming the old hard drive will be able to be connected to the new motherboard and XP will load up ok like before?

[kdjaC]

I am also assuming the old hard drive will be able to be connected to the new motherboard and XP will load up ok like before?

eh no, best bet is get a pro to look at your pc, im sure you know someone who knows about hardware. Whatever you do DONT GO TO PC WORLD!!!!!

Its either a PSU is dead or mobo is dead, regardless your HD is still safe and anything on it can be got back.

For all the tech support offered here noone has asked the simple question.

What is your current PSU and what PC did it come with?


kdjac

[kdjaC]

if it were a motherboard problem, you would have the motherboard coming on and beeping.

i reckon its not just a motherboard problem, but a motherboard destruction. a little scratch or a little electrical shock can destroy the whole thing and make it unresponsive. did you take anti-static measures when openning the PC?

?

A dead motherboard doesnt beep and a dead psu will not make a motherboard beep.

kdjac

[paul_oshea]

kdjac its not the PSU, as i got it changed and still nothing worked.

I cant remember the PSU off hand or the motherboard, but the dimensions of the motherboard are about 245 X 240 mm and its like this one ( with a few less pci slots ):
http://cgi.ebay.co.uk/Abit-KV8-Pro-S...ayphotohosting

It was a packard bell that I bought about 2 years ago from europc.co.uk. It was about 6 months old at the time.

I have a fair idea when it comes to the hardware, bar the motherboard ( obviously ) so i dont mind changing stuff and removing stuff as i have done a lot of it before.

[GavinZac]

?

A dead motherboard doesnt beep and a dead psu will not make a motherboard beep.

kdjac

no, a dead anything wont beep. However, if you read both parts of my post, I clearly differentiated between a motherboard problem and a broken motherboard.