Well, actually it’s taken more than one night, but tonight I finished the job after receiving the last of the spares I had to order…
A few weeks back our Kenwood Chef stopped working. It’s a KM400 model that we’ve had somewhere between twenty and twenty-five years, so really barely run in as these things go. Investigation suggested that the motor controller might have died. This is apparently a common type of failure on the older models, where some of the components on the speed controller board let out the magic smoke.
Hunting online I discovered that it’s possible to buy a few electronic parts to replace the likely failed ones and you’re up and running again, but if I was going to take the machine apart I decided I wanted to try to fix a few other issues at the same time: the strain relief bits for the cable had completely fallen apart, the clip-in cover over the top of the front end of the gearbox had broken and gone missing, and I’d had to bodge the speed control knob to fit back on after part of the mechanism failed a few years back. The first two could be sorted just by ordering spare parts, but the last was more tricky until I discovered that it is possible to replace the motor, all the speed controller electronics and the knob with what I assume are the parts fitted to more modern machines. It’s a more expensive option, but meant I wouldn’t have to fiddle about refitting new components to the controller board, it replaces the parts I’d bodged and the motor is slightly more powerful. In the end that’s the route I took.
Unfortunately removing the motor (which probably has to be done even if you just want to replace the controller components, or at least it would make it much easier) revealed another problem: two of the three screws holding the high speed outlet in place were corroded and couldn’t be removed. In the end I had to drill the heads off which meant I could take off the top of the casing and remove what remained of the shanks. These are 3.5mm screws which aren’t particularly common it seems. The one thing I know that uses them are patress boxes for light switches and power outlets. Otherwise the online spares places seem to sell them at £5+ for three screws!
Other than that, the entire swap was very straightforward. The only other minor niggle was that I had to replace a screw in the cover where the power cable is connected on the bottom of the motor housing with a self-tapper. On my original it went into a brass insert, whereas the new ones just have a hole in the plastic.
So, once again the Kenwood lives! It does seem just as noisy as it ever was, mind. I was kind of hoping that replacing the motor might quieten it down a bit. Perhaps one day I might have to look at servicing the gearbox.