The question is, what are the negative points to use this device for in-circuit measurements?
Perhaps someone has already tried doing this kind of thing.

 

The question is, what are the negative points to use this device for in-circuit measurements?

It depends on the circuit. You can usually do open/short junction tests, but you can't do any quantitative measurements (e.g. measure beta) because other components will likely interact with the device you're trying to test.

EDIT:
This is from the manual:

 

It depends on the circuit.

Yes, all factors need to be considered.

 

This holds true for any and every type of test equipment. It does not matter if it is analog, digital, or otherwise.

 

Yes, all factors need to be considered.

I hope you didn't pay a lot for that tester. A curve tracer with a scope would be much more useful. And you still need to test out of circuit to get good results.

 

I hope you didn't pay a lot for that tester.

It didn’t cost me much, but that’s not the point, of course.

 

It didn’t cost me much, but that’s not the point, of course.

When I was Googling for information, I saw that it was selling for $60-200. For what it does, there's no way it's worth even a fraction of that.

 

Circuits can be "designed for test" so that certain measurements can be made in circuit. There is a cost for this design choice and many manufacturers are not willing to pay that cost.

 

Circuits can be "designed for test" so that certain measurements can be made in circuit.

In this mode, it differs little from a conventional digital multimeter.

 

I redid the probes. I bought cheap tweezers and connected them instead of the original three. Now you can easily work with one hand. A good device for in-circuit testing of diodes and transistors with the most necessary information turned out.