Christmas blackout

A Christmas treat for me…

Christmas wouldn’t be complete without having to fix last years’ tree lights and this year was no exception.  It’s a tradition I look forward to and savour.

Gone are the days spending hours trying to find a faulty bulb, now due to the wide availability of cheap LED products, the thing that’s often likely to fail is the wiring, something which was much more unusual, a few years ago.  Manufacturers must make savings somewhere and I often wonder how retailers can offer new decorative lights, so cheap.  Compromises must be made somewhere I guess.

IMG_20181215_112843
FixItWorkshop, December’18, Worthing, Christmas Lights.

Being cheap, like a lot of things, makes them more disposable, which is a shame when things fail, often for trivial reasons.  This year’s blackout was caused by a couple of broken wires on the control box, which didn’t appear to have any obvious way to get inside.

We don’t like to be beaten in the workshop and sealed units and tamper-proof items are just seen as a challenge, rather than a deterrent.

Like many multi-function sets, the lights are operated via a control box with a switch, mounted in a plastic enclosure which appears sealed.  The fault was obvious here, just the main wire from the transformer had broken ‘flush’ with the control box, meaning that there was not enough wire either side of the break to re-join it.

The control box has no screws nor visible clips, holding it together, so it was time to break it open, using a small flat-bladed screwdriver.  The small section covering the wires snapped off cleanly, revealing several terminals covered in hot melt glue, annoyingly.  This meant that before any repair, the glue must be removed.  Several minutes picking this off with the screwdriver, revealed some conventional post terminals.  The fix was easy from there, just cut down the wire to make a new connection, remembering which way round they went, clean up the terminals and solder back together.  A little bit of fresh hot-melt glue to seal the connection and a bit more on the surface to be stuck together, and the cover was refitted.  I also fitted a little heat shrink to repair to reduce the chance of the cable from breaking again.

This slideshow requires JavaScript.

As I had the soldering iron out, I also did a small repair to the control box wire to transformer plug, which had also broken.  It was a case of cutting back two sides of the break, soldering, isolating with a small amount of electrical tape and sealing with heat shrink.

Now that’s all done, Christmas can now officially start.

Cost of replacement: £ 5.00 up.  Cost of repair: 1 cup of tea, heat shrink, tape and solder.

 

Outdoor LED porch light on the blink

Outside light on the blink

A couple of years ago, I made a light for our porch.  I wanted to ‘back-light’ the area under the porch with a subtle glow, when coming back home in the dark, handy when trying to find the front door keys.  I used a clear section of hose pipe, several clips and a strip of LED tape, commonly available from lighting suppliers.  I used a standard 12V power supply unit (PSU) from an electrical wholesalers’ and controlled the whole thing with a neat little PIR motion/ day-night detector.  It all worked quite well until the other day.

Whilst walking past the PIR detector the light came on in the usual way, but there was a strange ‘arcing’ noise, coming from the inspection panel, behind which I’d mounted the PSU.  The PSU seemed a sensible place to begin investigation.

It’s really irritating when manufacturers’ chose to make it so that a casing for something does not come apart, without breaking in to it.  This PSU was made this way and to gain access, I had to carefully lever the two halves of the glued casing apart with a screwdriver, breaking the glue holding it together.  It wasn’t working anyway, so what did it matter.

Looking at the printed circuit board (PCB) within the plastic casing revealed that the mains feed, presented as an IEC Kettle type connector in this case, had a ‘dry-joint’ and had begun arcing (small sparks) which left unchecked, would have caused permanent damage to the PSU.

With a small clean-up of the affected joint and a little soldering, the PSU was as good as new.  Sadly, the casing won’t be the same again, but as it’s hidden out of sight, I decided that a good wrapping of electrical tape around the two halves of the PSU casing was all that was needed.

Cost of a replacement PSU:  Circa £15.  Cost of repair: A bit of solder and my time.

Kaput Bosch AL1450DV Drill Battery Charger

An old Bosch battery charger gets a new lease of life.

These chargers often lead a hard life, working in dusty, hot and noisy conditions, so I guess many of these fail in time.

This Bosch unit is fairly common among Bosch DIY drill sets and this one had died catastrophically.  With the power applied, this one refused to give the slightest charge to a drill battery, once plugged in.

After some basic testing, I decided to change four components which would have caused the other to fail in a ‘domino effect’.  The cost of the replacement parts was just shy of £10, but definitely worth saving since second-hand units seemed to be changing hands for £40 on eBay, with their condition largely unknown.  The parts (two resistors, MOSFET transistor and diode/ transistor) were readily available online.

I recorded a short video to help others who might have a similar problem with theirs…