The interesting thing here is that the part has been substituted with another part that's comparable in quality and only slightly less expensive. The margins for counterfeiting this part can't have been very good.
It's pretty common to counterfeit electronic parts. I've come across counterfeit op-amps, exotic transistors, power transistors, ordinary transistors, capacitors, and even fake resistors which is amazing. It always just makes me wonder what is wrong, collectively and institutionally, with China? Making counterfeit goods of all kinds is apparently a common line of business in China. Is it just because _everything_ is made there so counterfeiting has proportionately shifted there as well?
While most of the discussion here is technical from engineering and business perspectives, your question digs more at the root of the problem: this is a cultural and institutional problem.
I live in China: people pinch pennies (or mao) here without taking into account the overall cost. This is why you have a large market for imported goods; even amongst the most nationalistic Chinese consumer, there is an assumption that imported goods are better because domestic products are made by cutting corners.
There's a strong suspicion of things that are priced cheaply but, bizarrely, people still buy cheap goods but are resigned to the product failing rather quickly. This just doesn't apply to electronics, but also to clothes, vehicles, etc.
There's a very strong tension between value-pricing and product quality. That is, there is a demand low prices but assume that the product quality is poor. On the other side of the spectrum there is a demand for high-quality "luxury" goods too. Thus pricing your product too low, even though it may be a quality product, basically indicates that it is a low-quality product.
Part of the myopia here is that people will cut corners without figuring out the benefit/risk ratio. That is, is it worth losing a contract to improve your bottom-line by a negligible percentage? Culturally (and I'm speaking in a broad generalization here) there's a desire to "win" at a contract... to make the contract be better for yourself than what's on paper. So even if the contract spells out your profit margin, it's a matter of pride to be able to improve on it (aka, "sticking it to the man"). With China's large population and widening gap between rich and everyone else, there's a perception that you have to get rich or die trying; no one else is going to help you... certainly not the government.
China's future could be a lot brighter than it is; the problems aren't technical.
Fake resistors? How is one supposed to fake a resistor? There are no manufacturer markings on them, just (easily testable) resistance/precision indicators...
Resistor is more than resistance. There is also other characteristics like power capacity, accuracy, tolerance, frequency responses, temperature coefficient etc.
The cheaper resistors are typically very loose for most of these characteristics. A tight characteristics means a high level of quality control at manufacturing, and this is usually lacking for the fakes.
For Op-Amps, the interesting spec is their frequency response as the op amps are not typically used in DC situations.
Especially if you get a batch that was manufactured in the original factory, and the faulty one put on the grey market. Indistinguishable product, but guaranteed and tested to be out of spec (might be a important parameter, or not).
Best interview question for EEs, IMHO: hand him/her an ordinary through-hole resistor, and say, "Tell me everything you possibly can about this component."
As a hobbyist, I'm curious: other than what the markings say (value and tolerance) and an estimate of power capacity, what would you expect the interviewee to be able to say about the resistor? Assuming you're not interviewing in a lab.
- Can they tell me the value and tolerance of the resistor by reading its color code?
- Based on the physical size/package, what's the resistor's power rating? Estimate if you don't know. Does pulsed versus continuous power make a difference?
- What kind of resistor is it? Metal film, carbon film, carbon composition, wirewound, ...?
- What's its temperature coefficient like?
- About what does it cost in small and large quantities?
- What kinds of parameters would you expect to see in a SPICE model?
- What are its noise characteristics? Johnson noise, flicker noise? Say I handed you a metal film resistor -- when would you want to use it instead of a carbon composition resistor?
- What does the resistor look like at RF? If it's a wirewound resistor, or one that was constructed by cutting a spiral groove into a film or substrate, what effect might that have at high frequencies? Estimate what its equivalent AC circuit might look like.
- Any concerns about quality, aging, and reliability?
- How about voltage coefficient of resistance?
The interviewee wouldn't be expected to go into much detail from memory, but they would definitely get extra points by just mentioning some of the factors. It would be fine if they answered the last question by saying something like, "There will be a certain change in resistance with applied voltage. It's going to be small and will almost never matter, but for precision applications I'd want to look it up on the data sheet." Basically I'm looking for an acknowledgement that there's no such thing as a truly linear or "boring" part.
That reminds me of a common practical joke from EE lab in college (~30 years ago): take the "right" value of carbon resistor (probably 1/4 watt, I forget how resistance mapped to time delay), plug the leads into an ordinary 120v power outlet, and walk away.
As the current flows through it, it'll warm up a little. Because carbon resistors have lower resistance at higher temperatures, as the resistor warms up, it'll start conducting more current, which will make it warmer, until a few seconds or minutes later (depending on resistance value, ambient temperature, etc.) ... "bang!".
All real components have real impedance, not just resistance. So at a minimum you'd expect a new EE grad to at least model a resistor as a combination of resistance, capacitance, and inductance, and explain what contributes to each (i.e. a wirewound resistor has more inductance than a bulk metal foil, or something). For veteran industry EEs you'd also expect them to mention things like microphonics, self-heating, thermocoupling, etc.
For commodity resistors, sure. There are high-performance resistors though, and they are usually packaged with a manufacturers mark (e.g. some of Vishay's line).
Also, the resistance of the resistor is only part of what I care about when I specify the part. Temperature co-efficient and the technology behind the manufacture can matter quite a bit -- and those are harder to test.
It's pretty common to counterfeit electronic parts. I've come across counterfeit op-amps, exotic transistors, power transistors, ordinary transistors, capacitors, and even fake resistors which is amazing. It always just makes me wonder what is wrong, collectively and institutionally, with China? Making counterfeit goods of all kinds is apparently a common line of business in China. Is it just because _everything_ is made there so counterfeiting has proportionately shifted there as well?