I just got back from the Pack Expo Show, where I was chatting with a few engineers about Chinese knock-offs. One engineer told me that recently they had a huge problem with a prototype system, only to discover that a key electronic component was a cheap knock-off. And, worse yet, they bought the part from a reputable distributor, who apparently had been conned themselves!
So much for the theory that buying from sources you know is always safe.
Anyway, it brought to mind this little gem of a story from the past submitted by Gerry Booker about mislabeled parts, which just goes to show while the circumstances may change, engineers have been wrestling with these sorts of issues for ages!
“These days I work as an instrument technician but back in the 1980’s I was an electronics technician working at a mobile radio manufacturing plant in Toronto, Ontario.
Shortly after being assigned to the trouble shooting area of the manufacturing line I began to find a repeating problem with the radios. They would have a very low output power on the transmitters and poor reception.
The problem turned out to be one particular capacitor on the circuit board which was actually soldered to the back of the board.
I at first thought that it might be a case of too much heat being applied and damage to the capacitor resulting from that. This was because about half of the units sent back to the repair people came back with the same problem. Then I replaced the capacitors myself, taking care not to overheat them, and I still had about a 50% failure rate.
These capacitors were a low value, as I recall about 27pf. I arranged with a friend in quality control to test the offending capacitors. They all turned out to be 300pf! This was in spite of the fact that the printing on the capacitors clearly indicated the lower value!
We then checked all of the capacitors in the 27pf bin in stores and found that around 50% of them were 300pf while the rest were 27pf. All were from the same manufacturer but it was apparent that they came from different batches.
We never did find out whose goof up caused this error but I think someone was in deep doo doo as a result.”
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