Strange problem with Bosch hedge trimmer

[Roger Mills]

My Bosch PHS66G hedge trimmer has provided valiant service for quite a few years . . . until today.

I was using it this morning, and it suddenly stopped. I checked all the usual stuff - fuse, power breaker, cord continuity, etc. - all ok. I then found that I could get the motor to run spasmodically if I shook it. I subsequently found that it would run if I held it upside down, but would stop as soon as I turned it the right way up.

Later in the day, I took it to bits, but couldn't see anything untoward. The brushes appear to have plenty of spring-loaded travel beyond what is required to contact the commutator. There is no end-play in the armature. The commutator was a bit dirty, so I cleaned it with some fine wet & dry and then a dab of white spirit - and hoped all would be well when I re-assembled it. But no - exactly the same.

Any ideas?

[newshound]

Break in the supply cable, probably near the strain relief?

[meow2222]

If you had a multimeter you'd already know. We can't tell from here.

NT

[Roger Mills]

I *do* have a multimeter (two, in fact) - but I haven't got enough hands to hold the probes on at the same time as operating the switch!

The switch, in the handle, is a fairly complex affair - with a button which has to be pressed before the switch can be operated, and with umpteen wires coming out of it since it operates some sort of brake when you let go of it.

Obviously you can't perform remote diagnostics - but I was hoping that someone may have experienced something similar and could have provided some pointers of what to look for.

[Kevin]

tape the switch in the on position and measure the continuity of the cables without it being plugged in

[The Natural Philosopher]

Unless its been buggered about I'd say a sticking brush..look for excessive arcing and a lot of black on the commutator. . Otherwise its probably as people say a bad connection.

Taking all connectors off and using switch cleaner and replacing them is a start, as is re-squeezing all crimps.

And gets some croc clips for your meter! Or phone a friend!

[meow2222]

TBH I've mentioned the only pointer there is. There really is no way we're going to know any more from here, testing is the only way forward.

You might use clamps on the switch, or a sheet of polythene folowed by several turns of tight tape to get enough tension. and it sounds like you could do with croc clip leads for the meter. After all you cant hold probes on and shake the appliance.

NT

[Mr Melvyn Stewart]

replying to Roger Mills, Mr Melvyn Stewart wrote: hello roger did you ever get to the cause of the problem as mine is doing exactly the same regards melvyn