Bosch AXT 2000 Rapid shredder not working

[Leif]

I have the above unit, which is about 12 years old, and it has stopped working. I used it this morning for a few minutes, turned it off, then a while later tried to start it again, nope. I’ve tried the following with no success:

I waited a few hours to ensure the thermal cutout had reset.
I changed the fuse.
I tried a different plug socket.
I took it apart, cleared out the dust inside, cleaned the sponge air filter, checked the safety switch looks okay. The cables inside look fine, no sign of frying or coming loose.

The unit is not blocked, and it doesn’t even try to start. The on off switch feels like it is working as it should, but nothing happens. It isn’t a dead capacitor, as that would cause it to make a noise while trying but failing to start. I can’t see why the motor would suddenly die, it was not stressed, there was no smell of overheating when I turned it off.

Does anyone have a cure or suggestion based on experience? It could be the switch unit that has broken, they are not expensive, but I’m wary of going down the replace everything bit by bit route, it can be expensive. My neighbour, an ex landscape gardener did mention that Bosch lawnmowers often fail due to a broken switch.

[Someone-Else]

As with anything not working, you should prove if it does or does not work first.
Obvious thing in view of what your neighbour said, check the switch, does it have a run capacitor? I was wondering if the brushes failed?

[Leif]

Thanks. I ordered a switch and micro switch then realised I might have a cheap multimeter lying around, found it and discovered that it has a continuity test function. The micro switch passed a continuity test, the main switch failed it. The shredder now works again. I also have a Bosch mower that doesn’t power up, so I’ll check the switch(es) with the meter.

You’re right, I should have tested first, ordered after.

It seems odd that a switch fails after relatively little use i.e. a couple of shreddings a year over ten years, so maybe a few hundred switch activations.

[Leif]

As with anything not working, you should prove if it does or does not work first.

Thanks again. I carried out a systematic examination of the lawnmower:

Replaced the plug fuse, no change.
Removed motor cover, brushes and wiring look okay.
Checked plug and external cable continuity, passed.
Opened up the switch casing, checked switch continuity, passed.
Checked the cable leading from the motor to the handle, continuity failed on one wire.

Then I noticed a clean break in the non working cable! It is very very easy to miss.

Aren’t multimeters great?