Hello everyone, I think I'm ripe for writing my first column of my own on this wonderful forum. Immediately I apologize if the text is a little clumsy, I do not speak English, I use Google translator. The idea is this: upload here a photo (or even better video) depicting the symptoms of bad microcircuits. Not too experienced A1 amateur builders like me would be able to identify a "troublemaker" from these photos or videos and replace him on their own without having to purchase expensive equipment. I am sure that every A1 builder has such situations during debugging, and the presence of a "room of horrors" - the name was invented by Uncle Bernie, will greatly simplify this task.
I'll start with the Signetics 74123 chip, board location B3. I had this "grandfather from the 70s", when I pressed reset, it did not stop displaying /////////, with a short hold, @ appeared, but as soon as I let it go, everything continued again. The selection method was used to find the problem and replace the "troublemaker".