Some of the most dangerous wall warts and leaded power supplies came from the UK in the days before switch mode techniques became common.
They were very poorly constructed and the workmanship was abysmal. Some of the problems were.
(1) Overheating causing the cheap plastic case to distort and sometimes catch fire.
(2) Bad regulation
(3) High ripple
(4) Components not tethered and inclined to move and fracture self leads or short to adjacent components.
(5) Poor quality mains leads which would fracture
(6) ...
And non Japanese TVs were nothing short of a disgrace at one time.
Even now some of the guitar amplifiers from the west are very poor.
And a certain car model catches fire because of poor electrical design.
You also hear unsubstantiated negative statements about the quality of cheap components on eBay for example. But, in most cases, they are fine, often they are just old stock. In one case, I got some 555 chips in the original RS packets- they probably dated to the 1990s. At the company I worked at when a production run had completed they would simply junk the complete stores content and order new components for the next batch.
I recently bought a load of components from cheap sources, mainly eBay. One item was a set of 2% metal oxide resistors, covering values between 1 ohm and 1 M ohm. So I decided to batch test the resistors. For a start you could not tell them apart from Allen Bradly, and in fact they looked like a famous brand item and, to top it all, the resistors I checked for resistance were in specification.
But there are blatant rip-offs: batteries being number one, but also power transistors, RF transistors, and high value electrolytic capacitors- you will always get rouges in any area of society. Why eBay and the Chinese government do not stop these forgeries in a mystery, because they tarnish the image of the whole electronics industry.
There is a lot of innuendo about Chinese electronic products, but the truth is that Chinese products have improved the quality of products radically and their low cost has opened up a whole new range of possibilities for home constructors.
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