That all being well and emotional. The poster has a point which you folks are too charged up to see.
Let me demonstrate.
See this thing.
In the same place there was this
RF-5800H-MP HF Manpack Radio | Harris RF Communications | Tactical Radios
and this as a test subject too
Military Communication Systems | Capabilities | ASELSAN
The first one was made by ordering components from Chinese factories using blueprints made in house.
The second one also had local blueprints but had components fabricated elsewhere,
The third is all US.
However, only one of them never shorted or had any major fault. That was not number 1 or number 2. It was number 3.
Only of them regularly had quality issues, it was not number 2 or 3.
The Chinese components regularly had faults and did not perform to specifications despite various visits by their factory heads themselves. It was only after rigorous QC did number 1 sort of start to work and its electronic boards did not have regular problems.
Funny thing, there was a chip in all three of American design and origin but manufactured in China which RARELY had faults. Clearly, there was serious problems in what the Chinese thought was quality and standard as to what the Americans were forcing them to stick to.
The fault did not lay with the Chinese engineers and workers, it lay with standards and expectations put on them. Which once they learnt were able to build just as good as the American equipement. Similarly, When the F-7P first arrived in Pakistan, it was REJECTED by the PAF and sent for various modifications in China.. these modification were adopted by the Chinese themselves who later improved upon them themselves.
On the other hand, quality issues have also existed in Pakistan. When the First F-6s were being serviced in Pakistan, many were lost due to an error made by Pakistanis who were fitting a component in reverse!.
As the Z-10 will go into combat, it will take input from real world usage and quality. Its weapons will be tested much more thoroughly, it will fly a lot more regularly and face a hostile environment.. and faults will happen. These faults will be reported back to the Chinese so that they can improve their product and make it better. So when that product also goes to the PLA, they will have real world inputs going into a much more improved system for their forces.
It has nothing to do with Chinese Engineering being bad, but with the basic idea that no-one(not even the Americans) gets it right the first time. Trial and Error is how good machines are built.