Can't comment on that specific model, but we have a kenwood Chef that died and all it was was a pcb that needed replacing. (the kenwood is now nearly 40 years old.)
We have a Sunbeam MX7900 (current model) that's decided to stop working.
A few years old now so it's out of warranty.
So I can work out what's happening with the speed controller, I'm just wondering what type of motor is in it ?, and would it depend on any feedback to the controller ?
Last edited by loopyloo; 12-12-19 at 09:36 AM.
Look Here -> |
Can't comment on that specific model, but we have a kenwood Chef that died and all it was was a pcb that needed replacing. (the kenwood is now nearly 40 years old.)
I'm out of my mind, but feel free to leave a message...
loopyloo (12-12-19)
Don't worry for now.
I traced it to a chip with no output, so I've ordered a couple of new ones to be here in a week.
Hopefully that will fix, it else I'll have to delve deeper.
Going deeper
I could find nothing for your particular model, but there is a service manual (with circuit diagram) for the Sunbeam MX7700 available for download at .
I would think that the electronics will be similar, so it will hopefully be of some assistance to you.
loopyloo (21-12-19)
Going back to basics. Have you connected power directly to the motor ?
This will narrow the search.
Depending on motor type, it could be brushes etc.
Last edited by Reschs; 21-12-19 at 11:22 PM.
loopyloo (24-12-19)
Yep, connecting the motor to mains was one of the first things I did.
The unit consists of the following -
Board 1/ for main power and motor speed control......no longer available.
Board 2/ for variable speed pot and motor on switch. (also has a couple of trimpots)
Safety switch for head down - motor will only operate when the mixer head is down.
Hall sense on motor.
Motor, motor on sw, head down sw and speed pot are working.
Board 1 main components : Triac (BTA16), reg (7905), micro (mc81f4204m) and an off line switcher (lnk304pn)
The motor circuit is : Line - head sw - motor on sw - motor - triac - neutral.
The speed pot and hall sense both feed into the micro.
The triac and reg are good. I replaced the lnk304pn cos I couldn't see what it was doing, so I know it's fine too.
I suspect the micro is wrecked so I think if I fit a total replacement controller is easier.
Any suggestions for a suitable after market controller from ebay ?
I should be able to fit it inside the unit using the same knob. Only thing is, the knob rotates 180deg so perhaps if I can utilize the same pot for the after market controller.
Last edited by loopyloo; 25-12-19 at 08:17 AM.
Answering 'What's that?' ... 10Mhz resonator for uPC ...worth checking if it's ok
loopyloo (24-12-19)
Might try one of these :
yep ok don merry xmas
loopyloo (25-12-19)
dashinson (25-12-19)
loopyloo (26-12-19)
Found this interesting circuit. Might be good as a backup in case the purchased one's not suitable.
dont like this circuit as it has a venerable zenner in the controlling the motor rails yukky
loopyloo (28-12-19)
Just thought I'd finish this thread :
The mixer was sitting around not being touched. That annoyed me.
So I did buy one of these a couple of months ago ( ), I wasn't too happy with the way it worked but today I decided to wire it in to the mixer and let the misses test it out on a cake. She said it was fine as far as she was concerned.
So there you have it. At least I now regained some table space.
TVguy (16-04-20),VroomVroom (17-04-20)
so you just wired the mains input directly to the motor?
loopyloo (17-04-20)
Not exactly. Currently the output from the Variable Voltage Controller I bought from ebay (refer post 17) goes directly to the motor. That's just so the wife could try it out.
There is a switch on the original mixer speed dial that turns on main power to the motor when it is first turned, and an inhibit switch to cut motor power when the mixer head is lifted. I will wire both those switches and the voltage controller output back into circuit through a relay so my wife can turn off the mixer at the dial without having to reset the speed for next time she turns it back on.
Last edited by loopyloo; 17-04-20 at 03:39 PM.
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