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.

Gaggia Classic machine wakes up to smell the coffee.

A Gaggia Classic Coffee Machine repair…

A simple repair…. That’s what I thought when a friend asked if I could look at his Gaggia Classic Coffee Machine, which had developed a nasty little leak when in use.  The coffee wasn’t all that good either, due to the lack of pressure available, caused by the leak.  In short, it needed attention.

IMG_3616
FixItWorkshop, Oct’17, Gaggia Classic Coffee Machine, with a leak.

The owner had already bought a repair kit consisting of the main seals/ gaskets that commonly fail, so I thought no problem, take to pieces, replace seals, happy days.  Er, not quite.

Once I’d stripped the machine down, pretty straightforward on these machines, the bare parts were exposed, which revealed the problem.  After being fired up briefly, not to make coffee I’d like to point out, water could be seen escaping from the boiler unit, a alloy bodied lump of metal, split in two halves, held together by 4 screws.  The boiler, as the name suggests, heats the water up with one heating element  and creates steam for the steam wand, with another element, all part of the same module.

After separating the boiler halves, I traced the leak to a faulty gasket, but crucially, one side of the mating faces was heavily corroded and unlikely to re-seal with a new part fitted on its own.  Remedial action was required.

This model is a few years old and a replacement boiler is still available on a few websites and prices vary from £40 to £60 at the time of writing, so at that price, starts to make the cost of repair unviable.

I decided that the face with the corrosion had enough material to withstand loosing some, so went about sanding the worst of the corrosion away before gradually moving on to  smoother and smoother sandpaper.

Because Gaggia Classics are fairly common, I decided to video this repair process as I suspect the corrosion affects many machines with age and just fitting a repair kit won’t cure the problem on its own.  See below.  I hope it helps anyone else with the same machine facing the same problem.

 

Once I was happy with the new finish, I fitted a new gasket and reassembled the boiler.  After putting it all back together, I purged several tanks of water through the system to remove debris, before attempting a cup of coffee.  Once filled up with my favourite Lidl coffee, the machine performed well once again with no leaks and the end product tasted great.

Cost of a new machine:  £249.00.  Cost of repair:  £4.50, plus time.