Logic Probe With Pulser
During my early days in electronics repair most circuit board use TTL ICs (74 series ICs) such as 74LS04, 74LS08, 74LS 86 and etc. One of the way to troubleshoot these ICs is to use Logic probe. You need to know the truth table of the logic gates before you begin to use the logic probe. And you must test it with power on. It was exciting during that time to see all the LEDs blinking at the logic probe. And if the result that I got did not match with the truth table then I know something had gone wrong. Of course one could directly replace the IC but the problem is those ICs was located in double side board and some in 8 layers board. The best is to troubleshoot it to confirm before replacing it.
Technologies change very fast and now most of the TTL ICs function already built into another power IC such as the MCU/CPU and etc. If you are a beginner and wish to learn what is all about logic probes and logic pulser i suggest that you click on the photo to visit the website.