Alesis (DM Lite) Drum kit without kick

Alesis Drum Kit gets a cheap repair.

A neighbour of mine is a talented musician in a local band and also teaches school children various instruments.  Some of his students learn the drums, which is most parent’s nightmare as any notion of a peaceful evening is shattered.  Luckily, electronic drum kits are an excellent way to learn with headphones, while keeping happy parents and neighbours.

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FixItWorkshop, Worthing, November’18, Alesis DM Lite Electronic Drum Kit
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FixItWorkshop,  Worthing, November’18, Alexis DM Lite main drum module

This kit was missing several beats and was hampering learning, so time for a visit to the workshop.  I’m no musical instrument repair specialist, but I thought that the drum kit must use electrical contacts, switches and rudimentary electrical components and I was right.

Two faults were reported; The kick/ foot pedal was intermittently not working and one of the drum pads was hardly working at all, unless you hit it with a sledge-hammer.  Time to see what was going wrong.

First up was the faulty drum pad.  Opening up the back of the pad was simplicity itself, just a few screws held the back to the pad.  Sandwiched between two halves was a sensor, a bit like a piezo flat speaker, similar to the type found in many toys with sounds.  I guess the principle here is that vibration detected by the piezo sensor is converted to analogue variable voltages by the drum kit’s circuitry.  While apart, I noticed that some of the copper detail tracks on the printed circuit board which had a standard 3.5mm jack socket (to allow a connection back to the rest of the kit) had cracked.  Looking again through my magnifying glass revealed quite a bit of damage, probably as a result of many Keith Moon wannabes.  Testing these tracks with my meter confirmed an intermittent fault, so out with the soldering iron, to repair the connection.  Plugging the pad back in, it was ready once again for more drum solos.

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Next up was the dodgy kick/foot pedal.  As the with the drum pad, the pedal would cut out intermittently.  A few screws held the pedal together, so only basic tools required.  See the slide show below for an idea of the construction.

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The fault with the pedal was similar to the drum pad.  Some of the copper detailing around the 3.5mm jack socket had failed and required some careful soldering.  I say careful, as applying too much heat at once would, likely as not, melt the casing of the socket.  One had to take care.

Once soldered, the pedal was much better.  I didn’t get a full 10/10 repair with the pedal since I think there was wear on the kick sensor, but it was an improvement none the less.

Cost of replacement:  £lots.  Cost of repair, my time, two cups of tea and some solder.

 

 

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.

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FixItWorkshop, May’18, Kenwood Chef Excel A902/A904, PCB before work.
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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.

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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.

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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).

 

Kenwood Chef A901 -a fishy story!

If your Kenwood Chef A901 starts to smell of burning, don’t despair, it can usually be saved.

I had an enquiry via this site from a fisherman who was very upset that his trusty Kenwood Chef A901 had given up the ghost.  Rather than using the Chef to make Victoria sponges, it had been used to prepare fishing bait.  It just demonstrates how versatile these machines are.

Kenwood Chef A901
FixItWorkshop, Oct’17, Kenwood Chef A901 with motor speed control fault.

Whilst it was in use, the owner witnessed a bang then the smell of burning before the machine came to a halt.  The plug was quickly pulled!

Whilst discussing the fault on the phone, I suspected that the fault was probably due to the failure of the motor speed control circuitry, which is known to fail with age.  I had carried out similar repairs to other machines, including my own (in this blog) so agreed to take a look.

I received the machine quickly and upon inspection, the machine had obviously been cared for and considering its age, was in good condition.  The smell of burned-out components was clear, lifting it out of the box.

Dismantling the machine and removing the motor on the A901 is fairly straightforward, providing you allow time and make notes on where things go.  The components that need to be replaced are very accessible and anyone with moderate soldering skills would be OK with this task.

Luckily, the Chef is very well supported by long-term aftermarket suppliers and I bought an off-the-shelf spares kit at £14.10 delivered, from KAParts (www.kaparts.co.uk) via eBay, featuring upgraded components.  This kit is a little dearer, but component technology has moved on since this machine was first on the market, so fitting anything else is a false economy in my opinion.

With the old components removed and replacements fitted, the motor ran smoothly and fully reassembled, the machine is now ready to mix bait mixtures once again.  Lovely.

Cost of a new machine: Circa £300 and up.  Cost of repair:  £44.10 (kit plus my time).

Here’s a little video I made of the repair.

Enjoy.

 

Samsung S4 mini GT-i9195 -cracked screen

I take on a phone screen replacement

I’ve never replaced a phone screen before, but since there’s a wide range of spares at reasonable prices available out there, I decided to take on this repair for a friend.  The screens on these and other smart phones are fragile.  They are made of finely machined glass, made to extremely high tolerances and therefore susceptible to damage from knocks and scrapes.  At this point usually, I might whinge on about how manufacturers do this deliberately to some extent, to bolster built-in obsolescence, but on this occasion, the break was due to the owner falling off his bike (off-road) and the phone hitting the deck, while in his pocket.  I’m amazed the damage wasn’t worse.  No hospital treatment for the owner on this occasion, just bruising and a dent to his pride.

The repair kit for such damage came in at a reasonable £8.99 and the eBay vendor promises to have the kit within a couple of days.  I’m sure you’ll all be waiting with baited breath to know how the repair goes.  I will of course keep you all updated.

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FixItWorkshop, Aug’17, Samsung G4 screen replacement.

Stay tuned.

17/08/17

The repair kit has arrived and there are lots of components in the box.  After watching a few (very good) YouTube videos on the S4, I think I’ll need a clear evening to repair the phone…

26/01/18

Opening up the phone’s back, just a plastic over, only 1 small screws held the phone together as ‘layers’ sandwiched together.

After separating the screen from the main body of the phone, it quickly became clear that the screen was in fact OK and it was the digitiser (digitizer in the U.S.) that has cracked and failed.  This meant that a new one was required, but after a conversation with the owner, we decided that the phone was now beyond economical repair.  New digitisers are available for the S4 at the time of writing.   The phone will be disposed of using an electronic recycling scheme.