Warning

tomsolomon

I just read a thread where someone was telling someone to poke some thing into a Power Supply Unit to see if the fan turns.
Now PSU's contain very large capacitors that hold a very large amount of electricity that can remain inside the capacitor for a long time after your PC is switched off.
Please do not go poking anything inside you PSU, or any part of your PC unless your are totaly satisfied you know what you are doing.
Besides the fact that your PSU contains lethal amounts of electricity, Your PC contains very delicate componentry which can be damaged by small amounts of static discharge from YOU.
If in doubt leave it alone and let someone who knows what they are doing fix your PC.

isofa

Good grief, a scary thought, I wouldn't poke about inside a PSU any more than I would a the back of a TV!

tomsolomon

The capacitors in a PSU arent anywhere near the size of what you would find in a television or monitor, but still worth steering clear of.
Some of the tv and monitor capacitors are well capable of dismembering your digits.

BritBrat

Easy to test if fan is working, get some tissue paper and place it near the fan outlet if it blows outwards it's working.

That is the safe way to do it.

Never poke anything metal into a power supply and don't take it apart for quite a while after it has been unpluged from the power supply.

iviv

Sorry, this was my fault, and I should have made myself clearer. I will go and edit my post, but stand by part of what I said. If a fan isn't spinning, it could be caught, or the motor could have died. Unplugging the PSU, grounding yourself, and using a non-conducting material will be the best way to find out.

Yes, I know capacitors hold their charge when the PSU isn't plugged in. However, the fans in PSUs are (From all the ones I've worked with) right at the edge of the PSU, covered with vents. It would be extemely difficult to poke something through the gaps in the fan blades and manage to touch the two legs of a capacitor.

FTD

I've had loads of PC PSU's apart and never had a shock. You cannot get a shock from touching a capacitor, you might if you touch the two parts connecting it to the circuit board, but it will not explode so you won't lose any fingers - I have no idea why the OP thinks you could! A capacitor with a rounded bulging top is one that has already exploded.
If a PSU is dead it's likely the fuse has blown on the circuit board, PSU's are easy enough to open up and replace the fuse (some of the cheaper PSU's have the fuse soldered on to the board instead of being replaceable - but still easy enough to unsolder)!

The tube in televisions and monitors are the parts most likely to give you a shock, not the circuit board, unless of course you have the board in your hands while the thing is powered on - But then you'd deserve to be shocked would you


FTD

tomsolomon

I think the vast majority of people would rather replace a unit than get out a soldering iron. And besides which, unless you have a background in electronics on a component level you should'nt even attempt a job like this this with the risks involved.
Its just bad practice to even suggest such a thing.

FTD

tomsolomon wrote: »

I think the vast majority of people would rather replace a unit than get out a soldering iron. And besides which, unless you have a background in electronics on a component level you should'nt even attempt a job like this this with the risks involved.
Its just bad practice to even suggest such a thing.

What? It's bad practice to replace a blown fuse? ? ? ?

Now you've really lost me - Are you saying you would rather replace a whole PSU rather than just the fuse, which 99% of the time is the main reason a PSU has died!!

FTD

tomsolomon

I wasnt refering to replacing a fuse. I was refering to people sticking soldering irons onto PSU's. And I wouldnt be worried about a capacitor exploding. I would be more concerned about the amount of electricity being dicharged form the capacitor. And isnt a tv tube in effect a capacitor anyway. I think we'll let the readers decide what they would rather do...

isofa

I think tom was just trying to help people out with some advice based on another thread.

I'm technically savvy, and have replaced and re-soldered plenty of components in my time, but advising people who aren't technically inclined to keep them and their fingers away from high voltage areas such as the inside of PSUs is of course good practice.

(Just look at the posts on this forum, most people get stuck with much more basic stuff.)

BritBrat

I'm technically savvy, and have replaced and re-soldered plenty of components in my time, but advising people who aren't technically inclined to keep them and their fingers away from high voltage areas such as the inside of PSUs is of course good practice.

Exactly how I see it. Better to be safe than sorry.

Trouble is you think you are telling someone to do something but what you don't know is what they actually do, it could be the totally wrong thing as they do not understand the instruction.