A friend recently asked to me look at a piece of kit that had been giving her trouble. It was intermittent and a swift whack or fiddling with the connections would usually bring it back to life but it had gotten to the point where it was unusable so she had send it to repair but when it arrived back it was completely dead and not wanting to fork out even more money or be without the device for an extended period of time asked me to have a look. She just needed to know if it could be reported or if she needed to go shopping for a new one.
It's a mains powered device and since UK plugs have a cartridge fuse inside, this is always the first thing to check. Unfortunatly the fuse was fine.
I opened the device, couldn't see anything obviously loose or damages so started checking the continuity of the mains flex from the plug to the device. a-ha. Both the live and nutral were intermittent.