Is 12 years too long to keep a toothbrush?

A Braun Oral-B electric toothbrush gets a new lease of life.

Let’s just clarify one thing straightaway; I’m talking about an electric toothbrush with changeable brush heads.

I was given an Oral-B/ Braun electric toothbrush as a birthday present years ago, which when you think about it, is a bit of a strange thing to receive as a gift.  Maybe the gift contained a hint?  Back then, these toothbrushes were not cheap, starting at about £60.00 if I remember correctly.  Today, a new equivalent is quite a bit cheaper.

In the time I’ve owned it, it’s had about 40 new brush heads and it’s just about to start it’s third non-replaceable battery.

Make and model:  Oral-B/ Braun 3756 931 41306

Fault reported: Battery won’t hold charge

Cost of replacement:  About £20.00

Cost of parts:  £6.60

Hours spent on repair:  1

Tools needed:  Small flat-bladed screwdriver, soldering iron

Sundry items: None

Repair difficulty:  5/10

Cups of tea:  2

Biscuits:  2 Gingernuts

Electrical items with non-replaceable batteries are so annoying.

A message to manufacturers:  There’s simply no excuse for it as all batteries are replaceable.

In my experience, items with ‘non-replaceable batteries’ contain entirely replaceable items.  The batteries might not be standard ‘AA’ items, but there’s a host of online suppliers that are ready to supply just about any power cell for any application, you name it, usually for a reasonable price that costs-in for the repair process.

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Now, I don’t know how long one of these toothbrushes is meant to last, but as a long-term test, I thought it would be interesting to find out.  After the first battery died, I decided to take the toothbrush apart, to see what was going on inside.

As you can see from the photos, there’s more within than one might think.  There’s a switch, charging circuit, timer circuit, over-pressure circuit, gearbox, motor, mini crankshafts and a battery.  Not to mention all of the tiny connecting parts all neatly engineered to work together, reliably.  It’s a small work of art really.

It makes me very sad that most of these toothbrushes will end up in landfill, after a few years.

The designers had clearly designed this toothbrush as a disposable item as the battery, despite being readily available from spares suppliers, was hidden, out of sight, under all of the gubbins.

To extract the battery (a simple nickel cadmium item) a full dismantle was required, in this order.

  • Prise off the top collar
  • Prise off the bottom cap
  • Pull out the main mechanism
  • De-solder the main pressure switch, charging coil, LED, and some other joints,
  • Take PCB off of battery carrier,
  • Split battery barrier from the main motor area
  • Remember the polarity of the battery, negative near the coil (a misleading ‘+’ there)
  • Reassembly, with the new battery is the same in reverse.  See pictures for hints.

Twelve years down the line and now on its third battery cell, the toothbrush is still going strong which proves that with a little tinkering, disposable items can be repaired and made to last longer.

It’s just a shame that Braun, the manufacturer, decided to ignore any notion of consumer maintenance.

 

 

Tommee Tippee Perfect Prep Problems

The right formula for a poorly Tommee Tippee Perfect Prep Machine

The owner of this Perfect Prep machine had reported that it had not been used for a while, then filled with water, powered up and … nothing.

Make and model:  Tommee Tippee Perfect Prep

Cost of replacement:  £70

Cost of parts:  £3.69 (plus my time)

Hours spent on repair:  1 (plus testing)

Repair difficulty:  6/10

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FixItWorkshop, Worthing, June’18, Tommee Tippee Perfect Prep.

I’ve repaired a machine like this before and I already had a theory about the problem, which went like this:

  • Machine not used for a while; watery scale deposits built-up in machine
  • Machine filled with water, with possible air-lock present
  • Air-lock causes bubble in heater, causing it to temporarily over-heat, safety thermal fuses blow

Dead machine.

At this stage, it was only a theory, so the only thing to do was to start wielding screwdrivers.

A few quick checks revealed that mains power was not getting to the main controller in the machine, which indicated that the safety thermal cut-out fuses had failed.  There are two on this machine.  A quick test with the multi-meter confirmed that both had failed.

After some dismantling, both fuses could be removed from the wiring harness.  Fuses like these are not available from the high street usually, but they are readily available online.  The manufacturer had used crimps to attach the fuses to the wiring, but I decided to solder the new ones back in place.  Care had to be taken as the melting point of solder is very close to the thermal rating of the fuses, so I came up with the idea of using a damp cloth wrapped around the fuse while doing the soldering.  A bit tricky!

Both fuses replaced meant that the unit powered-up and worked.  Great.

However, I wasn’t totally convinced that an air-lock wouldn’t happen again so I looked deeper at the machine’s plumbing.  There appeared to be a kink in one of the boiler tube feed pipes, so I decided to cut some material away, to prevent the pipe restricting water flow in future.

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All back together, the machine worked well once again.

 

Non-starter: Pure Evoke H2 DAB radio

My own radio gets the workshop treatment.

Who wouldn’t love a new DAB radio for your birthday?  Well, that’s what I had this year and I was thrilled to receive this Pure Evoke H2.  After choosing a suitable location on my desk, I quickly unpacked it, plugged it in and…nothing.  Booooooo!

The display backlight appeared to glow a little, but that was it and I was missing Today on Radio 4.

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FixItWorkshop, Worthing, November’18, Pure Evoke H2 DAB radio.

To save a quite frankly dull story, the returns and replacement process offered by the company who supplied the radio was hopeless.  But, after 2 months, I ended up with a replacement radio, in addition to the one I already had.  The second radio worked, albeit with some fettling required to the speaker to make it sound ok (another story).

Time to dig out the screw drivers as I had nothing to lose.

Just 6 screws hold the back on and with these removed, the radio’s innards were exposed.  Now, I’ve made radios from kits in the past using components I can hold with my fingers, but with this radio, the circuitry was teeny-weeny and I would have to have some luck to fix it.

I was in luck.  The radio is made up like a sandwich.  The front fascia is screwed to the cabinet and the back, that I’d removed, was screwed to the cabinet, from the other side.  There are data-style cables between the two halves and one of them appeared to be loose.  I carefully pushed the connector ‘home’ and then re-applied the power lead and wouldn’t you know it, the display lit up and it burst in to life.  Now we’re talking.

Thinking I’d sussed it out, I screwed the radio back together and had about a week or two of unbroken service, until the screen froze and then nothing. Oh no.

Re-opening the back of the radio, I suspected that the tiny soldered pins on the back of the multi-way connectors on the data-style cables, had been dislodged.  I have average sized hands for a bloke, but I needed tweezers to get the connectors on during assembly.  I wonder how much it would have cost to add an inch or so to each cable, to make manufacture easy.  As a consumer, I would have gladly paid the extra penny.  I suspected that this is how the original fault came to be as it wouldn’t have taken much more than a shove in the wrong direction to break the delicate connectors, due to the short length of the internal cables.

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Since this circuit board is a tiny stamped component affair, I had to be quick and neat with my re-soldering.  Each pin to PCB connector re-soldered, cables re-attached, back screwed back on and the radio worked once more.

Pure have a reputation for easy to use, excellent sounding products.  It’s just a shame they have seemingly penny-pinched on some of the internal gubbins on this model.  If yours develops similar symptoms, don’t give up, take the back off and have a look.

Cost of a new radio:  £40-90.  Cost of repair:  5 mins tinker time, one cup of tea.

Ultimate Speed Battery Charger from Lidl, on standby

Battery charger repaired at the workshop

My in-laws have an ornament on their drive, in the shape of a 2001 MGF roadster.  I say ornament because it’s fairly stationery, all of the time.  Even so, it’s battery gets topped up once in a while and the engine turned over when the urge presents itself.  Because the car isn’t used, the battery’s only means of charge is via a plug-in charger, my father-in-law occasionally hooks up.

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FixItWorkshop, March’18, Ultimate Speed (Lidl) Battery Charger.

The battery charger in question is an Ultimate Speed (Lidl brand) universal battery charger.  They’ve been on sale in the UK for a number of years at the £15 (approx.) mark.  They’re really good value as they allow ‘smart charging’ of car and motorcycle batteries without the risk of damage at a fraction of the price of the ‘big brands’ or a replacement battery.

However, this charger decided that it wasn’t playing anymore and refused to offer it’s charging services when recently connected to the MG’s flat battery.  On it’s way to the great bin in the sky, I managed to divert the charger via the workshop.

Once connected to the mains, the standby light illuminated, indicating something was actually happening, but upon connecting the low voltage side to a battery, making a charge selection via the single push-button switch, nothing changed and the whole unit remained on standby.  Pretty annoying.

Luckily, I have the triangular screwdriver required to undo the six screws that hold the (IP) ingress protected casing together.  Triangular screw heads are annoying and pointless as they prevent, in my opinion, people with a basic tool set having a go at a repair like this.  If you do fancy getting one of these tools, they are easily available on Amazon and eBay.

On with the fix.  With the casing opened up, my first port of call was with the switch itself.  Past experience has taught me to 1; start with the easy stuff and 2; these push to make switches fail all the time.  They’re in everything from door bells to cookers at the moment and when faulty, make the most expensive item and expensive paper weight in the blink of an eye.

To test the switch, I connected the charger to the mains and hooked up the low voltage end to a battery and simulated the button push switch by shorting out the switches connections on the circuit board.  Hey presto, the charger worked perfectly, every time.  The switch either needed repairing or replacing.

Because I’m a skin-flint, I opted to see what could be done with the present switch.  With care, these switches can be prised apart, using a sharp knife and the insides cleaned.  I took the switch apart which revealed nothing more than slightly corroded switch surfaces.  I can only assume that the product’s bold IP rated claim is a little over exaggerated and that some damp had wriggled its way to the switch and mucked it up.  With a cotton bud and switch cleaner, the switch surfaces scrubbed up like new and I re-assembled the switch lever and securing plat using a soldering iron to re-melt the plastic nubs holding the switch together.  No one would ever know it had been in bits.

With the circuit board returned to the housing, all six screws done up, the charger was back to rude health once more and ready to tend to the stranded MGF.

Runaway Hillbilly Golf Trolley…

Golf trolley heads for the hills…

Readers of this blog (I know there are millions of you) will recognise this golf trolley and I’m pleased to report that my first repair, the one to the motor, is still working perfectly.  However, the owner of the trolley contacted me with a (funny) problem.  Whilst recently enjoying a round of golf on the local fairway, the trolley decided to, by itself, begin to edge away from the second tee and then with some speed, head off in to the distance, without any operation of the dial switch, situated on the handle.  Whilst this seemed funny at first, I remembered that the motor on this trolley had the kind of torque that, coupled to small gearbox and wheels on a heavy frame, could do some serious damage, left unchecked.

Original photo taken in Aug’17, below.

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FixItWorkshop, Worthing, Aug’17 Hillbilly Compact Golf Trolley

Unlike many modern electric golf trolleys, it doesn’t feature GPS guidance, remote control or amazingly, a dead-man’s switch, which seems like a major safety oversight to me.  I’d have expected either a kill switch or dead-man’s switch* fitted to the handle on a trolley like this as the runaway scenario could never occur due to fail-safe nature of the switch being operated.  With one, the trolley would only run when the operators’ hand was on the handle or cut out when the kill switch is activated, as with the saftety cord mechanism, on a jet ski for example.  Perhaps the Mk2 Hillbilly Compact featured this.

*For example, a dead-man’s switch is usually fitted to something like an electric saw where the operator must old a handle-type switch to make it run.  Once the operator lets go of the handle, the motor automatically fails-safe and cuts-out.

On with the repair.  The trolley features some exposed connectors and cabling and it seemed sensible to check the continuity of the cables running up and down the handle shaft, as repeated trolley folding might have caused a problem with the wiring.  Fortunately, the cabling was OK.

The owner had mentioned that the handle, where the speed control switch is located, had got wet in the past, which made my alarm bells ring.

Opening up the handle, which only required a basic tool kit, revealed evidence of water damage and corrosion to the speed control terminals.  Luckily the owner of the trolley had stocked up on spare switches!

Removing the existing switch revealed intermittent continuity and varying amounts of resistance, which was not good.  A fault most likely to have been caused by water ingress or excessive shock.  The owner had supplied two ‘new old stock’ (NOS) switches.  Which one to fit?

From time to time, it’s downright sensible to either fit NOS or second-parts as they’re usually cost-effective and are more likely to fit over pattern parts.  But time can also affect apparently shiny parts.  This was a case in point.  I knew that the switch should vary resistance from open circuit to 10KOhms in either direction from COMM.  The old one didn’t and one of the ‘new’ parts only went to 2KOhms, so was not in specification.  Luckily, the remaining NOS switch worked fine and once refitted, and the handle reassembled, the golf trolley was ready to make the job of carrying clubs easier, once again.

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FixItWorkshop, Feb’18, Hillbilly Compact speed control switch, new and old- test NOS parts before fitting.

Cost of replacement trolley:  ££££ Cost of repair; £10 plus time.  Moral of the story; don’t assume NOS parts will work.  Test them first.