One of DocByers inputs reminded me of a unqiue troubleshooting method I thought up - others my have come up with the same idea so please do not claim i stole anything from anyone.
Does anyone remember the good ol' freeze mist that would leave a nice frost on the components? Well, if you can still get it, here's a technique for tracing current loading of power supplies and components. Freeze the suspect area or the output of the loading down supply with the "frosty" mist. The circuit path drawing the current will defrost VERY quickly. Continue down this circuit path with the freeze mist until you get to the suspect board or component. I have used this method on a couple occassions when a very common supply voltage is being loaded down and found the faulty component very quickly. It is also a SAFER method than over-fusing and watching what blows.
Another: Use your etching tool on the lightest setting to test for intemittent connections on boards. It provides a good low level vibration for forcing failures in cold-solder joints,e breaking leads, etc.
5 volt loading on a circuit card with gobs of IC's: besides the freeze mist method above, a fluke temparature probe to measure the IC temps or even your finger tip is a handy mehtod to find where the current is turning into heat. The temp probe can also find IC's that are DEAD and not generating any heat.
Quote from: LarryH on 01-03-2006 -- 10:55:39
It is also a SAFER method than over-fusing and watching what blows.
There is the safe way, and there is the fun way. They are seldom ever the same...
Good info LarryH! I always appreciate learning new troubleshooting techniques that don't require me to reverse-engineer the equipment. My troubleshooting technique usually involves some cursing, followed by a lot of depression, another bout of cursing, and then usually some measure of success. :-D