I encountered difficulties when testing LM239 comparators in a circuit. Not only do leaks appear at the inputs, which disrupt the external voltage divider and, as a result, change the response thresholds, but also cross leaks occur between 4 comparators, which are extremely difficult to discover.
At the moment, I use the method of complete replacement of all comparators. With this approach, I get one out of 6 comparators that is faulty.
Accordingly, I want to have (buy) a device that tests these comparators. First of all, I want to know the name of such a device, if anyone uses something similar.