Explosive Chef

Another Kenwood Chef A901 gets the Workshop treatment…

There’s been a steady flow of poorly Kenwood Chefs through the workshop of late and the new year started off with yet another.  A customer got in touch with reports of smoke coming from her Chef A901, a machine which had given years of faithful service to her family.  As a result, she was very keen to see what could be done.

img_7876
FixItWorkshop, Worthing, Jan’19, Kenwood Chef A901.

As usual with Chefs of this age, the 5 machine feet had deteriorated and now resembled squashed dry Blu-Tac, so had to be replaced.  I replace the feet to most Chefs that come in.  Not only do the feet prevent the machine from moving all over the place when in use, they provide a gap for air to be drawn in to the motor for cooling, so it’s essential the feet are in good condition.

img_7868
FixItWorkshop, Worthing, Jan’19, replacing the feet on a Chef A901 (others similar).

The feet are inexpensive and are easy to fit.  If you decide to replace yours, consider coating the existing ones with something like WD-40, a few days before you try to extract the centre pin or you risk snapping it off in the machine base, as it will likely be ceased.

On with the repair.  The speed control circuitry had failed, specifically a capacitor and resistor, a common problem on older machines, had gone pop.  As usual, the correct repair kit was bought and fitted. With careful soldering and a dab of heat transfer gel on the new triac and the job was complete.  Nice.

With any Kenwood Chef, I always check the motor end-float, the allowable spindle movement north and south.  The end float in this case was a little lose and required adjustment.  A small grub screw with Allen key head allows this adjustment and with a bit of trial and error, the end float was now spot-on.  Poor end float on these machines usually makes the speed control ‘wobbly’, especially at lower speeds.  With this one adjusted correctly, the motor now ran smoothly through all speeds.

Job done.  The owner of the machine was so pleased with my work, she even bought me a new packet of Custard Creams.  Fab.

This slideshow requires JavaScript.

Cost of replacement: £400 and up.  Cost of repair: £11.24, plus my time and Custard Creams!

Another Smoking Kenwood Chef Excel A902/ A904

I’ve repaired a few Kenwood Chefs recently, but this one seemed worthy of a mention on these pages as it’s slightly different to the ones I’ve repaired so far.

Many Kenwood Chef accessories are usable on Chefs from all eras, due to logical thinking by the designers over the years and this is something to be applauded as it reduces waste.  For example, the beater on a 1970s machine will fit one from today.  An interesting fact for any occasion.

I’ve repaired many A701s and A901s, but this was the first A902/4, so I thought I’d share some of my repair experience in order to help others.

The owner contacted me explaining that she’d been using the family’s cherished Chef to make a cake when a plume of smoke started coming from the mixer.  The smell was bad and she’d quickly disconnected the unit from the mains.  The owner then contacted me to ask ‘was the Chef worth repairing’?  Of course it was!

I suspected the infamous speed control components which tends to fail with age.  However, this model featured extra components all mounted on a neat printed circuit board (PCB) which is fixed near the motor.  A reasonably priced repair kit, with new rubber feet was available online so I ordered one up straightaway.

Opening up the A902/4 is a similar job on many Chefs and after removing a few screws, the motor and gubbins is available for maintenance.

As suspected, two out of the three capacitors on the PCB had blown visibly, due to crystallisation and general fatigue, so these needed to be replaced.

PCB
FixItWorkshop, May’18, Kenwood Chef Excel A902/A904, PCB before work.
PCB renewed
FixItWorkshop, May’18, Kenwood Chef Excel A902/A904, old and new components.

As all the components are PCB mounted, each part must be de-soldered first, contacts cleaned before re-assembly which is time consuming, but satisfying and even though I’ve done this kind of work many times before, I always take a couple of photos and mark wires with a pen or label, as it’s very easy to make mistakes later.

The kit included replacements for the faulty bits, plus some additional parts which should be changed as a matter of course.  I also chose a kit with replacement rubber feet for the machine as the ones fitted had squashed ‘flat’ with age, a very common problem with the Chefs of this vintage.

New components fitted, the motor ran sweetly once again, without smoke, wobble or extra noise.  It’s worth noting that the A902/4 is quieter than earlier Chef models and is probably worth seeking out if you’re in the market for a second-hand unit.

Another ‘happy little Chef’ leaves the workshop.

 

Cost of new machine: £400 plus.  Cost of new parts:  £15.24 plus my time.

Raucous Kenwood Chef A701a

A noisy Kenwood Chef A701a gets a gearbox rebuild.

This Chef had been sleeping quietly in a kitchen cupboard for some time before being woken up to make cake mixtures once again.  The owner had owned the mixer for many years from new and was sentimentally attached to it.  I fully sympathise, they’re great machines.  It had been used many times in the past and then packed away as new machines came and went.  Having decided that there was still a place for the A701a, it was fired up.

The owner didn’t remember it being quite as noisy and wondered if something was wrong with it.  She got in touch and brought it in to the workshop.   After listening to the mixer at varying speeds, we agreed that perhaps it was a bit noisy and that further investigation was required.

 At this stage I must confess at this repair has been on the bench for a long while..!

I think the A701 is my favourite Kenwood Chef product as it’s very elegant, beautifully proportioned and almost over-engineered.  It comes from a time where built-in obsolescence was a swear word.

White removed
FixItWorkshop, Oct’17, Kenwood Chef, A701a.

On with the problem.  After disconnecting the gearbox by removing the drive belt, I checked the motor for general wear and tear, the brushes and speed control mechanism and I concluded that it all seemed OK and working smoothly.  The gearbox however did seem a bit noisy when turned manually, nothing hideously graunchy, but a little rough.  To be honest, it would have probably survived, but I wanted to open up the gearbox to make sure that it was as it should be.

Whilst removing the Chef’s casing around the gearbox, I’d noticed traces of grease around the joints and various power take-offs.  All models seem to do this to an extent, but this one seemed to be quite bad.  Closer inspection revealed that some of the grease had escaped out of the seal between the two halves of the gearbox casing.  Opening up the casing revealed that the grease that was left had been pushed to the corners of the space within the gearbox and that the gears were a bit dry, this was probably the root cause of the noise.  The planet wheel that drives the beater was also bone dry.

Luckily, there are plenty of suppliers who can supply rebuild kits for Kenwood Chef gearboxes, including new gears and grease.  The gears in this seemed serviceable, but it seemed very sensible to replace the lubricant with the correct 130g of Kenwood gearbox grease, which is food safe.  I used ‘Kenwood Chef Restore’, an eBay seller and the kit was a reasonable £10.99, including P&P.  The kit included the main gearbox grease, white grease for the planet gear and sealant for the gearbox casing.

IMG_4570
FixItWorkshop, Oct’17, Kenwood Chef A701a, repair kit from Kenwood Chef Restore, eBay.

Before replacing anything, the first job was to clean out all traces of the original grease which had gone very sticky and was contaminated with general wear.   The first pass clean involved using paper toweling, followed by water and detergent, before a final clean with brake cleaner, which removed the last few traces of grease and dirt.

With the gearbox refilled and resealed making sure the spacers were re-fitted to the correct parts, the drive belt re-fitted with just enough slack, the gears sounded much sweeter with the final parts of the casing reassembled.  One last point to note is that I used silicone sealant on the blender attachment power take-off plate in replacement to the one fitted, since the original seal was well past it (see below).

As a finishing touch, I replaced the existing machine feet which had turned to mush with replacements from Sussex Spares (eBay shop) for a very reasonable £2.70, delivered.

The Chef was now ready to prepare cake mixtures again.

Cost of new machine: £300 and up.  Cost of replacement parts: £13.69 (plus my time).