Our very first post at Circuit Board Problems was about an application note created by Huntron that is a basic flowchart of the electronic circuit board troubleshooting process. We thought the chart was spot-on and asked for permission to share to which they granted.Lo and behold, we see that Huntron has posted a new article […]
Troubleshooting
Using V/I Signature Patterns to Troubleshoot Bus Circuitry
One of the more difficult types of electronic repair tasks is troubleshooting bus structures on complex digital microprocessor based circuit boards. Many identical address and data bus lines share the same electrical characteristics and make the fault finding process a challenge. However, you can use the repeating nature of this digital structure to your advantage. When […]
Look Close then look CLOSER! The Importance of good Circuit Board Inspection.
One of the first steps in troubleshooting an electronic circuit board is to perform a visual inspection. We did this with a recent stepper motor driver that had failed and did not see any issues. The next step involved building a signature analysis test to perform some power-off diagnostics. This process took about a half-hour […]
Troubleshooting a Switching Power Supply – Part 2
In Troubleshooting a Switching Power Supply – Part 1, we had replaced U1 and CR12 based on the analog signatures from the Huntron Tracker showing them as bad. On the rescan, the unit (for practical purposes) passed when compared against our known good reference signatures. There were no catastrophic problems indicated that would make us […]
Troubleshooting a Switching Power Supply – Part 1
We recently received a switching power supply that failed in the field so we took the opportunity to do some troubleshooting and discuss the process here on CircuitBoardProblems.com! Of course, like any good troubleshooters (and according to the PCB Troubleshooting Flowchart) we gave the power supply a good visual inspection. On the bottom side of […]
Solder Balls!
Here is a manufacturing process issue that turned out provide an interesting insight into how hot, liquid solder can react if it gets out of control. Initial testing with analog signature analysis shows a resistive difference on only one pin of a transistor (top image; top row of signatures, far right signature; green is good, […]
Anatomy of a Transistor Failure
We recently purchased a new video microscope and were looking for something interesting to inspect. Digging through our box of bad electronic parts produced a bad power transistor. Utilizing a set of sharp cutters, we performed surgery on this poor TO3 package device. Before showing the images from the inside of the actual device, here are the […]
Finding Bad Electrolytic Capacitors
As many of you may already know, electrolytic capacitors are one of the more common failures on electronic circuit boards. They have a hard life filtering all of the AC noise out of the DC voltage lines on the PCB. Over time they degrade and eventually the equivalent series resistance or ESR becomes too high […]
PCB Troubleshooting – Start with the Connectors!
If you have been troubleshooting circuit boards for a length of time then it may come as no surprise that many printed circuit boards (PCB) are damaged by surges, spikes and torrents of nasty over-current eruptions coming from the outside. Of course, the connectors on the PCB are the interface to that dangerous outside world […]
Circuit Board Troubleshooting Flowchart
Question: Does the world need another blog cluttering up the internet cyberspace! Answer: Absolutely! Especially if your interest is troubleshooting electronic circuit boards and all of the subjects that revolve around it. Question: What will you find on this site? Answer: Tips, tricks, white papers, technical bulletins, web site links and more all dealing with […]