eirik@elf.tn.cornell.edu (Eirik Fuller) (04/09/90)
I have a shop light that stopped working (one bulb lights, one doesn't), and for fun (not for profit) I'm trying to fix it. I've isolated the problem to one component, which looks like a diode. I did this by swapping components one by one. Now I'm not sure how to replace the bad part, i.e. what to buy. Each of the two circuit boards has two resistors, one capacitor and, apparently, one transistor and two diodes. If I swap just the little diodes (signal diodes?), the problem follows the bad diode. It has a little red glass case. The larger diode, in a black case with a stripe, is ok on both boards. This diode, if that's what it is, has no label. Any ideas what it might be? My ohmmeter (a Radio Shaft LCD Digital Autoranging Pocket Multimeter) shows that the good one is completely open (meaning that the meter doesn't exceed the device's voltage drop, I guess), and the bad one measures about a megohm. Any suggestions for other tests I might use to find out what it is? My meter's manual says it only measures diodes with a drop of less than a volt. In case it matters, the light is manufactured by Lights of America in City of Industry, CA. No, I don't have a schematic :-) Please respond by email; I don't read this newsgroup. If appropriate, I'll post a summary of useful responses.