Dodgy Wiring.
I used to work for Maplin Electronics, back in the nineties before it became all Tandy-like. For those of you who don't know Maplin (including our Forren readers), it's a bit like Radio Shack - selling electronic parts, electrical items, tools and gadgets.

I have seen some of the most stupid, reckless and downright dangerous examples of wiring you can possibly imagine. The expression "the customer is always right", if we had stuck to it, would have resulted in deaths.

Some of the stupidity is difficult to explain unless you know anything about electronics/electrics, so I won't go into too much detail, but there was one example that warrants a mention:

We sold a vast range of kits, for people with soldering irons to make anything from amplifiers to oscilloscopes.

One of the most complex kits was an Analogue Synthesiser keyboard. It had a staggering component count, consisting of a dozen tightly packed circuit boards which needed assembly - including a "diode board" for decoding the 49-key piano keyboard switches which had a count of about 350 components on it's own. Needless to say this kit was intended for expert kitbuilders only, and advertised as such with words like "advanced" and "expert constructors only".

We offered a "get you working" service for kits, where our HQ techies would fault-find and reconstruct where things had been built wrong, but this was quite expensive. We had one of these keyboard kits returned for this service, as some of it wasn't working.

The customer had constructed the synth meticulously, but only certain sections of the complicated circuitry worked.

Giving it the once over, before sending it away to HQ, he had SUPERGLUED every component in place, rather than soldering. It had taken him WEEKS. He eventually paid three times the price of the kit for one of our techies to solder all of the components in properly (in a well ventilated area, of course).
( Doctor When May your wife shat and chipper, Wed 31 Dec 2003, 10:44, Reply)