PC is totally dead.

telemarks

On many PC's round the back near where the power cord goes in, is a simple rocker switch for the power supply. Is this On? Or has it been knocked into Off?


Failing that while round the back, unplug the kettle lead, and swap it out for another one, (like to one to the monitor) just to rule it out.


If its not the switch or lead, then the next suspect is the power supply. The good news is on many PC's these are designed to be replaced, and if you are confident with a screwdriver are an easy DIY cheap job, or should not be that expensive in a PC shop (its usually a 10mins job).

[Deleted User]

Le_Kirk wrote: »

Or and I don't know why/how this could happen, is there a switch on the PSU that has been inadvertently switched off?

Ahh, good point.

Has the OP tried turning it off and (forgotten to) turn it back on again

moonpenny

PC is HP Pavilion bought 10 years ago. Number on receipt is S5206UK. It is running Windows 7.

Looking at back of tower there is the smallest green light near the bottom but when I press the button on tower it goes off and won't come on again. (Pressed the button so many times that I don't know if it's on or off now)
If I put the plug into another socket the light comes on again but won't come on by pressing button on tower.

A.Penny.Saved

Having a cheap Multimeter can be helpful. They cost a few £, you might get a very basic one in £ land. They can make testing fuses easy via the circuit test function. That makes it quick and easy to rule out failed fuses.

If the PSU has failed then the fuse might of also failed. As I mentioned a PSU tester would verify whether the PSU is dead which is fairly likely once all the basics have been excluded.
https://www.ebay.co.uk/itm/Digital-LCD-Computer-SATA-HDD-Power-Supply-Tester-20-24-Pin-4-PSU-ATX-BTX-ITX-UK/283000050630

[EDIT] if the PSU is over 10 years old then it is almost certain to be the PSU. Even excellent PSU's only have a max of 10 year warranties such as Seasonic.

grumpycrab

Colin_Maybe wrote: »

You've piqued my interest, what would this achieve?

[holding power button down for 20secs with mains switch OFF...] drains voltages off the motherboard and resets your RAM memory (may be an old wives tale...:-)

MangyDog

So there is a green (standby) light on the motherboard when the psu is connected? But dies when you try to power it up?
Could still be the PSU at fault. Able to provide a standby current but fails when a real current is pulled. It rare though when PSUs fail they tend to fail in interesting ways... IE with a flash and smoke. (like mine did earlier this year, lucky it didnt take out the motherboard/cpu/graphicscard/harddrives.....)
But the computer being 10 years old as you said. Its also possible the CPU or motherboard chipset has failed.

But im still hedging bets on PSU...

What is the specs of your computer, how many harddrives does it have and what is the power rating of the PSU?

If you have a spare PSU thats of the same rating or higher you could try pluging that in and see if that works... If it still doesnt work. It could be any number of other problems, and depending what you use your computer for might be cheaper just getting a new computer.

If the motherboard has failed. You could buy a new motherboard for 50-150 quid, depending on what cpu and performance level it is...
Its also possible a single capacitor has died on the motherboard thats causing a short to ground when its powered up. But youll have a hard time finding what one (unless its turned into popcorn, or chard black) and without a circuit diagram wouldnt know what rating youll need to put in.

Some comfort though... Your data is intact. So no matter what happens, even if you have to buy a new computer. You can always just put your old harddrive into the new computer have access to everything you had before. (just might need a little reorganising)

moonpenny

Am sorry but I know nothing about computers and the words you use may as well be Chinese.
What is PSU and CPU and how do I find what the power rating is? It says on the front of the monitor 2009v. Is that it?
The tiny green light is at the back of tower near where the computer lead is plugged in.
Other than that there is no life at all.

There was no smell of burning or anything like that, it was working perfectly the day before than nothing when I switched it on the day after.
I leave everything switched on but turn the tower and monitor off when finished.

Don't know if its important but for ages now it has made sort of a double clicking noise occasionally when in use?
Just one hard drive.

moonpenny

Apologies, no green light on the back. It is hard to get to and I think it was just reflecting green when I moved one way.

MangyDog

Im assuming this is a desktop computer? Have you taken the side panel off? Or is there a window? I had assumed one of the two as you said there was a green light on the motherboard?

If i assumed wrong. Take the side panel off. And when its plugged in is there any lights on the motherboard? The motherboard is the main big circuit board roughly 30cm x 30cm (if its a full sized desktop)

The PSU = Power Supply Unit, Is a boxed shaped unit screwed into the case (if a desktop) Its what the kettle plug connects to on the computer. This would be at screwed to the top or the bottom of the case. The power rating in Watts should be view able on a label at the side of the PSU.

This PSU is most likely whats at fault and most likely needs replacing.

The reason why you need to take note of the PSUs watt rating is because PSUs come in ranges from 100-1500 watts (sometimes more) This is so low end less powerful machines dont need as much power as the bigger higher powered computers. So why put in a more expensive power supply for a low end computer.
PSUs are also standardised. So you dont have to go to the manufacturer of your computer to get this component. As mentioned above dont just get any old cheap chinese power supply, there quality isnt good most of the time and can be a fire hazzard.

If we narrow down that it is just the PSU thats broken, then you can buy a known brand one from any decent tech shop for a reasonable price. For a lower to mid range computer say 200-400 watt psu. You could get a decent known brand one from OCUK or Ebuyer for around 20-50 quid maybe less....

Just first take note of the WATT rating of the psu youre replacing as thats the one the manufacturers deemed to be suitable for the spec of your machine.
You could also play it safe and get a higher watt rating psu, and if you have added more mechanical harddrives to your computer it might be advisable to do so... As it may have been the extra harddrive that tripped the old PSU over by driving it a little too hard.

I hope this rambling hasnt make things more confusing, as really its not. Its like a simple jigsaw puzzle, but its obvious where the pieces go because the shapes and slots are really simple

A.Penny.Saved

moonpenny wrote: »

Am sorry but I know nothing about computers and the words you use may as well be Chinese.
What is PSU and CPU

PSU = Power Supply Unit
CPU = Central Processing Unit the part that runs your software.

and how do I find what the power rating is? It says on the front of the monitor 2009v. Is that it?

It might say on the back of the PSU it will be in Watts. Otherwise there might be something online on the manufacturers site where it might say what PSU is installed. Taking the side off the PC so you can see inside often shows the power rating. A typical power rating can be calculated by an online calculator such as:
https://outervision.com/power-supply-calculator
You will need to know what CPU, graphics card etc are installed which will mean finding out the info online because the PC is not working so software cannot find the information.

The tiny green light is at the back of tower near where the computer lead is plugged in.
Other than that there is no life at all.

There was no smell of burning or anything like that, it was working perfectly the day before than nothing when I switched it on the day after.
I leave everything switched on but turn the tower and monitor off when finished.

Be aware that this does not turn off the PC 100%. It still draws a tiny amount of current and can still be affected by power mains spikes which can be wearing on the PSU.

Using a mains switch such as an extension is a better method. There is usually a switch on the back of the PSU but that might not be easy to reach. It is best to isolate from the power when not using it.

Don't know if its important but for ages now it has made sort of a double clicking noise occasionally when in use?
Just one hard drive.

It sounds like your hard drive might be failing. After 10 years it has lasted well.