Does anyone know how to fix the speed control on a Kenwood 701a? Our machine starts instantly at far too high revs, spraying the contents of the bowl everywhere! As far as I can tell, the top speed is about right, but it will not slow down to a reasonable lowest speed.

Dick Morris, October 2006

i have a kenwood prospero km240,am not able to control the speed any more any idea to help please

Sabetta Mario, October 2022

My Kenwood chef slows down the speed when dough is hard.

charles, January 2018

Kenwood A901E--centre black knob is coming out of control dog, so to turn I have to push in black knob to make contact with shoulder of dog. Any ideas??

henry.todd, November 2017

I have sparking inside the motor and a blown1.5mf mains capacitor. If I replace the capacitor will that stop the sparking in the motor?

peternic, November 2013

Do not assume the capacitor tested okay hence leaving it on the PCB as is. What you measured is the capacitance only, and of course it might read the full value, (-) or (+) a little bit, but the real capacitor measurement is actually its ESR (Equivalent Series Resistance), and you only can achieve that with an ESR meter. When the CAP's internal resistance goes up, it will not allow power through it, in other cases, it happens intermittently. You can get an ESRmeter off eBay from about £30 to expensive hi-tech ones.
You need one for all electronics you may want to fix, if of course you are qualified to do so, otherwise replace the damaged capacitor with a new one just to be sure.
Having said that, I am not responsible for any DIY you may undertake, mistakes are deadly fatal.

Abu Abdillah, April 2013

i had the same issue on a more recent kenwood (KM300 kenwood chef),
I changed the triac, and also one capacity,
and finally it was one normal-looking resistance that need to changed. (i tested each resistance with an ohm-meter, and saw one that was broken)

Grégoire, March 2013

Maybe a different variant, but this is how I fixed mine:

http://fixedmyself.blogspot.com.au/2012/10/kenwood-chef-speed-control-problem.html

Andi, October 2012

orange cable goes to the screw loaded with a spring which adjusts the plate, andthen it goes down to one side of the connections to the bushes, atleast its like that on the km300 very similiar setups

alyeti, June 2012

I have taken a km200 apart to find a fault and discovered i needed to replace the brushes, that was a fortnight ago and i have forgotten where a cable went, its orange and it comes of the spring/screw on the orange circuit board but i dont know where it goes to, can anyone help please?

Harvey, January 2012

I was recently given a KC A901 which worked, but seemed to start very fast and stopped getting faster after speed 5 on the dial. After a couple of uses it went pop and emitted smoke. I replaced the scorched capacitors and 56ohm 2w resistor. All worked again but the speed dial problem remained. Your thread below has been massively helpful and I have found the speed control screws and adjusted them. I am now getting a full range of adjustment on the dial and around 60rpm at low speed, but the machine sounds really rough at anything up to about speed 4 with a lumpy uneven sound and vibration. Can anyone advise? It feels so bad at low speed that I'm tempted to readjust it but then the A929 slicer attachment is terrifyingly fast and unusable. Any advice on this would be hugely appreciated. Also, can anyone advise on the correct rpm at maximum speed? Can adjustment of the control screws make the machine go too fast, or will it only go as fast as it should?

lottybun, September 2011

I was wondering if someone has a speed control wiring diagram for Kenwood Chef A701A. I have taken it apart and found a fault. Now after a few months I have forgotten how to connect the 510 ohm resistor to the circuit.

Can anyone please help?

Abe, August 2010

try turning the two screws on speed control plate its under the motor cover (plastic) you can test first by putting a small screwdriver through the cover and turning the screw clock wise. if this does not work. go to. kenwoodchefusedmixersandspares and go to products then motors.

portmick, May 2010

Richard, the burning smell comes from flour deposited on the large resistor over time. This eventually dissipates when the machine has been run at slow speed for a while but can worry anybody who is adjusting the speed downwards for the first time.

paul [at] camtutor [dot] co [dot] uk

Paul Bird, February 2010

Paul Bird is quite correct but I don't understand the comment on a 'burning smell'.
My daughter's mixer packed in with a flash and a puff of smoke. This turned out to be one of the 0.1mf capacitors which had blown apart. This was replaced with a new one after testing the circuitry. All is now in order again with the machine running at 55rpm at low speed. I am not going to adjust for 5rpm.
Before taking off the speed control plate containing the electronics it is a good idea to measure the height of the two spring loaded screws (for adjusting the speed when necessary) in order to get a ball-park adjustment when replacing and testing after a repair.
Removing the wiring from the circuit board can be quite a mission and one requires a steady hand in order to prevent the soldering iron from touching components. In addition a soldering iron spring loaded solder remover is essential. Then you will find that the wires are still attached to tabs which crimp the wire tightly and when prising off the wire they tend to break.
I ended up extending the wires by soldering on new lengths (correct gauge of course) and insulating the joints with shrink tubing and the application of a hot air gun. With the extra lengths now available it was relatively easy to re-solder them to the board.

Richard Harrop, July 2009

The motor tends to speed up over time and needs adjusting back down to 60rpm at the slowest speed control setting on the side, by screwing in the two slotted screws clockwise, accessible through the plastic casing under the motor, using a long thin flat ended screwdriver (Health & Safety warning - with an insulated handle)

Try a quarter turn clockwise each then turn the machine back over and try it on the slowest speed, put your hand on the mixing attachment holder and let your fingers gently catch the protruding bit each time it comes around while watching a second hand, you are looking for about 60rpm and the movement at this minimum speed will be somewhat erratic. There will also be a burning smell from the resistor but don't worry about this. Once the flour has burned off the smell will go.

If it still exceeds 60rpm on the slowest speed control setting then turn the machine over and turn the two screws in a bit more, but evenly on each side to keep the centrifugal switch bracket evenly balanced.

Continue until about 60rpm is achieved and ignore the burning smell.

paul [at] camtutor [dot] co [dot] uk

Paul Bird, May 2009

I have the same problem as others (black wire arrached to mains input to ? fell off when investigating a fault).
This is on a circa 1966 model.
I would appreciate a circut diagram of the speed controller.

email to : td0jd9s02@sneakemail.com

fixie, February 2009

I have a Kenwood Chef A701A mixer which I've just taken apart. Slow running is rough and the large 450R resistor gets too hot and starts smoking on slow speeds. I've worked out the very simple circuit diagram but have no idea of the concept behind the centrifugal force speed control mechanism. Does anyone know what this type of speed control is called? Is the large Plessey 0.1uF 1000VDC capacitor a motor start capacitor or is it just to suppress interference? I'll be replacing that capacitor for a start. I'm confident this will be quite easy to sort out. No way, should anyone throw away their old Kenwood Chef mixer if you just need a new capacitor and perhaps a new 450R resistor. There is no Triac in my mixer. How can I post photos here of (i) current components (ii) my wiring diagram and (iii) my new components once I've bought and fitted them?

A701A fan, February 2009

I followed Kens instuctions and it now works perfectly. Thank you Ken.

Jack, South Yorkshire., January 2009

You need to replace the capacitor with a 0.1 mF 275VAC mains capacitor and the the load resistor with a 450 ohm 15W or 20W wirewound resistor. It will then work fine. I can provide a circuit diagram if you want.

wilsonsRus, December 2008

I had the same speed problem with my old Chef. Took it to the local dealer who enquired at the Kenwood service place - they said that the repair would be costly, as the whole control unit needed replacing with a newer version. They then offered me a great deal on a brand new one instead. I took the new one!

Vall, November 2008

I said 2 wires in the sleeve probably go to the brushes. Maybe not, as I realised when I pressed the return key too soon.

Soldered joints in my 701 rapidly fell apart as the motor was being handled and manouevred into position. The components give clues as to their position and function, like the ferrite inductors.

However, I am not too happy as to whether ones' insurers would accept a repair and maintenance job which is nearly right. Hence the need for a wiring diagram.

Brian, June 2008

I wonder if some kind soul could describe or otherwise send the connections for the Kenwood 701 centrifugal speed controller. Mine got messed up after some of the wires broke off and I can't recall where they all went. There is for example a sleeve of 3 coloured wires 2 of which presumably go to the brushes. How are the rest connected to the tab strip?

Brian, June 2008

the triac on the speed controller has failed short circuit. replace this with a 500 volt 10 amp triac from say Maplin.

john g, January 2008

the triac on the speed controller has failed short circuit. replace this with a 500 volt 10 amp triac from say Maplin.

john g, January 2008

I have a Kenwood Electronic KM200 but I think the speed controller is the same as the a901. I bought the triac
BTA08-600B from Maplin for approx. £1.30. All the other components on the circuit board tested ok. Capacitors were not shorting, and there was not sign of swelling. The diodes tested OK. The triac is described as the speed controller in other forums. I de-soldered the part and soldered in the new one. It worked first time.

I would recommend using a de-soldering tool though. (http://www.maplin.co.uk/Module.aspx?ModuleNo=97040&C=Maplin&U=SearchTop&T=DESOLDER&doy=14m5).

I now have 2 working :) Kenwood chefs - as I bought an A901 and fixed a blown capacitor on that.

Ben, May 2007

Thanks to maniac and ken. Did as you advised, and machine works perfectly

Dickm, January 2007

If this is the 701 & 701a models, then there is no triac, it's done with a mechanical govenor with bob weights on the bottom of the motor, this makes and breaks the current to the motor via a contact. This contact is on the circuit board that the dial moves up or down to adjust the speed. Look closely and you should see two long thin screws with springs that hold this board in position. Adjustment of these sorts out the speed. See which way the dial moves the board when you turn it to max, adjust the screws the opposite way. If you are cunning you dont need to take it apart as these screws are accessable from underneath. 1960's electrical standards apply, lots of 240 volts just waiting for the careless, so adjust only when unplugged from the national grid. Darwin Award awaits otherwise.

maniac, December 2006

Pretty sure that you get into the machine and speed control is adjusted via two screws with springs. Turn the machine upside down, open the spring base, take out four screws, take out two screws holding slider in place, slide plastic cover out of the way. Two screws with springs should be on side opposide control knob.

ken, December 2006

Sounds likely that the TRIAC has blown and needs to be replaced.

A901User, November 2006