Jig Saw

[Little Jim]

We have a Skil jig saw at work, nothing fancy, just a reasonable quality standard jig saw.  We do not use it much, in fact we bought it a couple of years ago when the old one expired in a cloud of blue smoke and today is the first time we have needed it.  It does not work.   The little work light comes on so there is power getting through.  We can turn the motor by gently pushing the fan blade round with a small screw driver, so it is not seized.  There really cannot be much wrong with it given that it is unused and has power.  Before we start dismantling it anything else we could try to persuade it to work? Going to see the Accounts dept. and asking for a copy of the receipt so that we can claim on the guarantee is a non-starter, and anyway I suspect that it is over 2 years since we got it.  It would be a shame to have to bin it for probably a very minor fault.

[Kim]

Might be an internal fuse or something...

[Feanor]

I expect you are right, there will not be much wrong.

But the only real approach you have open to you is that standard one when dealing with Broken Things, as you mention.

You need to open it up, visually inspect, make some measurements with a meter to see where juice is getting and where it isn't, and only then can you determine how to proceed.
Anything else is just guesswork.

If it's a variable speed thing, could be the speed controller has died, or the finger operated trigger is not engaging an internal part properly.

[Little Jim]

Thanks for the suggestions.

I hadn't thought of an internal fuse, and if there is one I bet it is glued in with molten lead.  Our lot are good with BIG spanners, but I wouldn't trust any of them with a soldering iron.

It does have a variable speed switch so we can have a look at that plus see if the trigger does everything it should inside, but I was guessing that as the work light came on the trigger was probably working OK on the basis that it would just be one switch to power everything, but maybe not. 

[grams]

On my el cheapo Aldi cordless jigsaw the work light stays on after you release the trigger, so it must have its own circuit.

A common design these days is to incorporate the trigger into the same circuit board / module as the speed controller, and it’s cheap enough to add an extra wiper for things like the light.

[Diver300]

I have had a couple of power tools with bad connections on the switch assembly. Many tools have a variable speed trigger, so the trigger operates a variable resistor which tells the speed controller what speed is needed. If that makes no connection, the desired speed is seen as zero. The light will still come as there will probably be a real switch for safety, and / or to make sure that it doesn't take any power when completely off.

[salar55]

Have had a few pro tools over the years, the most common breakdowns have been the switches , as they have speed controllers built into the switch. Last failure was a 36v sds Bosch   Sometimes it's better to buy a new one,  spare parts switch was priced at £150  so bought a newer version.