Power Switch

[itsmarkdavies]

I have an older model MESH ATX Tower and recently it would not turn on - i pressed the power switch on front of case and absolutely nothing happened. I bought a new power supply and still nothing. By process of elimination i think it must be the power button / lead on front of PC, as i can short the 2 pins on the motherboard where power lead plugs in and PC boots and runs perfectly till i shut it down. Problem is i cannot find anywhere that sells spare case leads / switches - any suggestions ?

Many thanks,

Mark.


mark.davies@npower.com

 

[G0AOZ]

A few thoughts...

As a work-around, does this machine have a reset button on the front? If yes, trace the wires back to the motherboard connector and swap 'em with the power switch wires.

It might be worth physically checking that the wires for the power switch are still intact all the way from motherboard to the actual switch itself. Any breaks etc?

Often these small momentary switches are of a fairly common size. The one I have in front of me right now is about 8.5mm x 8.5mm square, and has 6 connection pins poking out of the rear. It snaps into place in the back of the front panel of the case. Any redundant cases lying about that could provide a spare...?

ROGER - G0AOZ.

 

[edfair]

In a worse case problem I have used a reset switch from an older machine and let the switch hang outside the case by the lead wires.

Finding replacements can be a pain.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[itsmarkdavies]

Thanks for your reply Roger, i tried using the Reset button / wire but this does not work with the power switch either (which may mean that it's the pins on the motherboard that only respond to manual shorting ? !).

I have inspected all the wires and they appear to be intact and in good condition, but unfortunately i don't have another case to nick spares from.

Is it possible that the pins on the motherboard need cleaning, and if so how do you do it ? - they're so close to bottom of case i have a job getting anywhere near them at the best of times.

 

[itsmarkdavies]

Thanks Ed, i'd be happy to let the lead hang loose, but i cannot find ehere to buy ANY kind of appropriate switch / lead.

 

[stduc]

Try connecting a multimeter on the Ohm settings to the 'sockets' that connect the switches to the mobo. Use a couple of paperclips to make the connection to the multimeter. Failing a multimeter a 1.5v cell and a suitable bulb would suffice.

What I am suggesting is that you test the switches. They may just have dirty contacts - so once you can see if they work at all, try blowing them out with air, or even WD 40. But you really need a multimeter to see if you are winning and getting zero ohms.

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]

 

[edfair]

Just slipping the connector on and off several times should be enough to break through any corrosion on the pins.

This kind of reminds me of the molex issues with the SS50 bus issues of long ago. Where you needed to use a "pink pearl" eraser on the pins regurlarly to clean the built up contamination.

You could verify the switch by putting the powerswitch on the reset pins, short the power pins, then press the power switch to see if it resets.

I would suspect that a computer store that does upgrades might have old cases lying around that they could scrounge a switch from.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[wahnula]

Any decent electronics store would have that switch or an analogous device. Tinning/soldering/shrinkwrapping to the header you're done. Were I faced with this I would "stealth" the button rather than letting it hang out...install it in the rear panel or one of the PCI slots.

 

[itsmarkdavies]

Many thanks for all your replies - i know it is definitely the lead from the switch to the mobo now - dismantled it all and one of the green/black twisted wires is split !.

I know nothing about soldering so it looks like a hunt round PC shops to find a spare (if anyone knows a UK website i can get 1 that would be great) - thanks again for all your useful tips.

 

[electronicsfreak]

Id visit local computer store, they probably have an old switch or something laying around you can probably get for free off of them.

There is a point in wisdom and knowledge that when you reach it, you exceed what is considered possible - Jason Schoon

 

[r0gerc]

Mark - if it's only a break in the wire, could you repair it with one of those little terminal strips? They come in lengths of about 10 or so and you cut off what you need. I think you can get those in most hardware shops. Maplins sell a variety of small switches too.

 

[acewarlock]

Cut, Splice. Tape.