Cold GHD hair straighteners

GHD 4.2b hair straighteners with a new fuse.

Someone got in touch with a set of GHD 4.2B hair straighteners, which wouldn’t warm up.  Not even the light would come on.

Make and model:  GHD 4.2b hair straighteners

Cost of replacement:  £85.00

Cost of parts:  £2.89 (plus my time)

Hours spent on repair:  1 (plus testing)

Repair difficulty:  5/10

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 These older hair straighteners are well supported with spare parts and their design means that, with a systematic approach and basic test gear, the fault can be identified and parts replaced, fairly easily.

The thermal fuse on these straighteners can fail, even though the heating elements and associated wiring and circuitry is just fine.  A combination of age and accidental rough handling can affect the life of the fuse, so it was the first thing I checked on these straighteners.

It was first time lucky in this case.  The fuse tested open-circuit.  To prove that the rest of the circuit was working, I made a temporary short circuit to the fuse connection and the straighteners powered up OK.

Time to order a new fuse.  Using an eBay shop (SiriusHairUK), a fuse was ordered and it arrived very quickly, great service.

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With the fuse re-fitted and the heating element re-installed the rest of the hair straighteners were ready for reassembly.  Using basic tools, the straighteners went back together well and after final testing, they were ready for use again.

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.

 

The heat is on…

Dimplex DX300T heater gets repaired in the workshop.

I acquired this Dimplex heater as the previous owner had reported that it had tripped their electrics and smelled of burning, it was perfect material for the workshop.  The owner had given up on it and I felt like I could give it a second chance.  This is the usual way we end up with much of the stuff in our home.

Now, this heater is only a few years old and on the face of it, it looked in reasonable condition, with just a couple of scratches, so it would be a shame if I couldn’t get it working.

With electrical faults like this, I always check the basics; the condition of the flex and mains plug etc.  I then measure for resistance to earth from either live or neutral to see if there has been any electrical shorts, that would have triggered the reported fuse incident.  All clear.

Through the top heat vent, I had a quick look at the inside of the heater to see if any stray paperclips or other metallic item had found its way to the heating element or wiring creating an electrical problem, again, all clear.

Upon checking the mains plug again, something didn’t seem quite right.  It felt a little ‘warped’.  I’d already checked the fuse for continuity via the live and neutral (there was resistance), but it was time to take it out to have a proper look.  The plug on this heater was a ‘moulded-on’ type, with no screws and the fuse carrier was accessible from the outside, should it need replacing.  Upon levering the fuse holder out, the plastic carrier sheared off, revealing burned plastic and signs of melting.  The plug was toast.

I decided to break the plug cover off and see what was going on.  The plug had ‘run hot’ for some time causing the casing to melt and smoulder and the excess heat had probably caused excess resistance, exacerbating the problem, making the previous owners’ electrics to go pop.

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With the cover ‘broken off’ the plug, I was then able to cut back the internal connections and remove the cable from the mouldings, without sacrificing the cable length, which was a good job as the flex was quite short anyway.

I always keep a few replacement ‘quality’ mains plugs in the workshop for occasions like this, as not all moulded plugs are terribly well made and the melted one I had here was a good example of what can happen when the quality of the plug can’t match the potential current flow required.  The heater is rated at 3K Watts (max), which would mean a current of 12.5 Amps, which is close to the 13 Amps fuse fitted.  Poor quality materials and connectors would generate excess resistance and therefore heat.  The resistance was probably detected by the sophisticated minature circuit breaker in the previous owners’ electrics board, which was a good job as who knows what could have happend if the plug had been next to something flamable.

With a new plug fitted, the old fuse re-fitted, the heater sprung to life and didn’t seem to draw excess current when checked.  A nice cheap fix and I didn’t even have to take the heater apart.

Cost of a replacement heater:  £50 (circa)  Cost of repair:  One cup of tea.

Tommee Tippee (not so) Perfect Prep

A formula machine is repaired in the workshop.

This fix was actually carried out during the summer, 2018.

A friend of mine brought over a broken formula making machine for me to look at.  It had been stored after their first child had out-grown it and since having another baby, it was now needed again, urgently.  Following a couple of years in storage, it was brought out, plugged in and after briefly coming on, it failed.  No lights, no hope.

These machines save time and effort by allowing water to be heated rapidly and mixed exactly with the formula powder, to produce consistent results every time, perfect for new exhausted parents in the middle of the night. So it was important that I got this working quickly.

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FixItWorkshop, Jan’19, Worthing, Tommee Tippee Perfect Prep machine

After removing the back, I was presented with an electronic control unit, some solenoid valves and a heater, plus some other environmental sensors such as thermostats.  The plug fuse was OK, so it was time to check if power was getting to the machine.  It wasn’t.

This machine features a couple of power control devices; two  thermal aluminium ‘can-style’ fuses in-line with the heater, plus a thermostat on the output of the heater itself (to regulate heat).  After testing for continuity, it appeared that one of the can fuses had failed.

These fuses are common across a wide range of appliances, such as coffee machines, fans etc and are cheap, just a few pounds.  It could be that a temporary air-lock in the heater caused a hot-spot and therefore that excess heat caused the 172 degree fuse to pop.  It was worth a try to replace it and see what happened.

I replaced the fuse and re-assembled.  After filling with water and powering it up, normal service was resumed.

Since I replaced the fuse, the machine has been in continuous service for many months, so I can conclude that it was probable that the over heating was temporary.

I created a short video to help others who may have similar problems with their machine.

Cost of a new machine:  £90.  Cost of repair: a few quid and a few beers.

 

 

Parrot BeBop Drone knocked off perch

Sadly, I couldn’t save this Parrot

I seem to be having a run of failed repairs at the moment and while it’s disappointing to write-up a repair that didn’t succeed, it’s important to learn from failure.

A colleague asked me to look at a Parrot camera drone recently as one of the drone’s motors wasn’t running correctly.  The fault developed after a visit to a lake where it got a little wet.  It turns out that this model isn’t water-proof, despite the £300.00 price tag!

After drying out, when powered back up, one of the four motors wouldn’t spin at full speed.  These motors seem to operate in several phased windings and it would appear that one of the motor’s phases was missing.

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FixItWorkshop, Aug’17, Parrot BeBop drone

Upon opening up the drone, I discovered that the PCB had indeed suffered water damage along its main processor.  However, three of the motors were fine and camera was working OK.

The double-sided printed circuit board (PCB) presented me with a dilemma.  This PCB was fitted with extra tiny components and multi-layered board technology, presumably to save weight and cost, so a repair using conventional soldering techniques was unlikely to get good results as the excessive heat would more than likely damage other components.  Located near the wiring connector that connects to the motor that wasn’t working properly, were several tiny surface mount fuses, one of which appeared to have failed.  Assuming I could locate the right component, attempting a repair on a PCB like this would more than likely yield a molten mess! At this stage I could have used a conductive glue to bond in a new component or temporarily bridge the fuse, but on the basis that I couldn’t guarantee a repair and the fact that there seemed to be water ingress to the whole PCB, I decided that a complete PCB replacement was probably needed.  Sadly, I had to return the drone back to the owner with the bad news.

Pump, ready for the dump

This asthmatic car tyre pump came in to the workshop with little going for it.  The owner had been very close to throwing it away when he came across my website.

This AirMan pump is designed to be plugged in to a car’s cigarette lighter socket and provide quick and convenient car tyre inflation.  This one was dead.

On first inspection, the fuse was OK, the switch seemed to work and all connections seemed sound, when tested with a multi-meter.

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FixItWorkshop, Worthing, May’17 AirMan Car Tyre Pump, repaired

Off with the cover…

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FixItWorkshop, Worthing, May’17 AirMan Car Tyre Pump, repaired- cover removed

When the motor was removed from the cam driving the piston, the bit that drives the pump, it spun freely when power was applied, using a battery in the workshop.

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FixItWorkshop, Worthing, May’17 AirMan Car Tyre Pump, repaired- gear wheel

Seemingly, the centre spindle was protruding far beyond it’s specified reach, causing the pump connection rod to it it during rotation.  Why?  To be frank, I wasn’t sure. I can only surmise that the vibration and heat had caused the flywheel/ toothed drive to slide outside of specification.

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FixItWorkshop, Worthing, May’17 AirMan Car Tyre Pump, repaired- washer

There appeared to be room for a small washer to take up the excess space, so I fitted one I had lying around.

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FixItWorkshop, Worthing, May’17 AirMan Car Tyre Pump, repaired- pump now in line with washer

The washer, once fitted, allowed the flywheel/ toothed drive to sit ‘square’ in-line with the pump.

Once resembled, the pump ran freely and was ready to inflate, once more.

Cost of a new pump, circa £20.  Cost of the washer, circa 5p.

Sterling Power Products Pure Sine Wave Inverter repaired

Inverter, repaired in the workshop

For those wondering what an ‘inverter’ is, let me give a quick explanation:  It allows one to use a mains operated device on the move, using a power supply from a motor-home, car or boat, as an example.  An inverter ‘inverts’ a smaller voltage to a larger one, usually for most applications.  Most inverters sold turn either 12 or 24VDC to 240VAC or 110VAC.

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FixItWorkshop, April’17, Worthing, Sterling Power Products Pure Sine Wave Inverter Pro Power SB 600W

The owner of this one had accidentally connected the input wires the wrong way around, effectively reversing the polarity.  Not good.  Upon hearing a little ‘pop’ the owner quickly disconnected the power!

Having never worked on an inverter before, I turned to the manufacturer for advice.  Sterling Power (UK) were not able to supply any product information on the phone nor via email and were generally not very helpful at all.  They did offer a very reasonable 25% discount on a replacement, but were not able to offer much else to save the one I had in the workshop.  Never mind.

Back to the problem.  Checking the basics, the ‘accident’ had appeared to knocked-out three 25A soldered PCB fuses.  Temporarily by-passing the fuses revealed a working unit, so replacing the defective fuses was a good idea at a very reasonable £1.50.

The fuses are mini-blade 25A automotive fuses.  Once removed and the new ones soldered in place, the unit worked once more.

Cost of parts, £1.50, cost of replacement unit, circa £160.00.

I’ve also covered this repair overview in a video:  https://youtu.be/nmnSRwQdSvY