Since I seem to be the local go-to for any dead electrical equipment, this brand-new Silverline polisher has landed on my desk. Purchased cheap from an auction this was dead on arrival. Checking the fuse revealed nothing suspect, so a quick teardown to find the fault was required. Above is
After having a couple of the cheap Chinese PSUs fail on me in a rather spectacular fashion, I decided to splash on a more expensive name-brand PSU, since constantly replacing PSUs at £15 a piece is going to get old pretty fast. This is the 30A model from Mercury, which
The other day at the local canal-side waterpoint, this TV was dumped for recycling, along with another later model Colour TV. This is a 1970’s Black & White mains/battery portable made by Thorn. It’s based on a common British Radio Corporation 1590 chassis. Having received a soaking from rain, I
Well it’s time for a new DMM. After the last pair of eBay El-Cheapo Chinese meters just didn’t last very well, I decided a proper meter was required. This one is a Tenma 72-10405, stocked by Farnell for under £60. Not quite as many festures as the cheapo Chinese meters,
I almost forgot about this bit of kit, that came with one of my LED torches as a Lithium Ion charger. As I never plug in anything that comes from China via eBay, here’s the teardown & analysis. Here’s the unit itself. It’s very light, and is clearly intended for
Here’s an odd & sudden failure, the power adaptor for a Samsung device. It’s been working for months & on being plugged into the mains today the magic blue smoke escaped. It’s one of their 2A models, for charging bigger devices like tablets. Strangely for one of these chargers, no
Here is an AVR powered optical tachometer design, that I adapted from the schematic found here. I made a couple of changes to the circuit & designed a PCB & power supply module to be built in. The original design specified a surface mount IR LED/Photodiode pair, however my adjustment
Here is a cheap no frills microwave oven, which died after a few weeks of normal use. Cover removed, showing the internals. Front of the microwave is on the left. Closeup of the timer unit. Cheap & nasty. Magnetron removed from the oven. Antenna is on the top, cooling fins
Here is a cheap no brand hot laminator. This pulls the paper, inside a plastic pouch through a pair of heated rollers to seal it. Top removed, heater assembly visible. PCB attached to the top cover holds LEDs to indicate power & ready status. Here is the thermostat & thermal
Here is a cheapo 500W rated ATX PSU that has totally borked itself, probably due to the unit NOT actually being capable of 500W. All 3 of the switching transistors were shorted, causing the ensuing carnage: Here is the AC input to the PCB. Note the vapourised element inside the
This is an old USB 1.1 hub that was recently retired from service on some servers. Top of the unit visible here. Bottom label shows that this is a model F5U021 hub, a rather old unit. PCB is here removed from the casing, Indicator LEDs along the bottom edge of