I would look for a shorted tantalum capacitor hanging somewhere on the 10V rail. If you hook 10V from an outside source to the 10V buss, you'll probably find it's drawing all kinds of current. The 10V regulator circuit will go into fold back before burning up. This is by design. I usually hook a source of 10V at about 1.5A and look for smoke. It's usually one of the tantalum capacitors that starts to smoke. Once it's done smoking, problem solved!!
I have lost track of how many shorted tantalums I have had over the years. When they occur in the B+ of the high current PA supply, they simply burn up and th problem fixes itself. The 10V regulator doesn't have enough guts to burn them up, so they stay shorted and wait for someone to find them. Often times it is a cap on the mixer board. Those are fed though a resistor of a few ohms. Good luck, Scott Scott Zimmerman Amateur Radio Call N3XCC 474 Barnett Road Boswell, PA 15531 w4wsm wrote: > I was up on the hill this afternoon loading new firmware into a controller > when my UHF Master II went down. Didn't even touch the thing... > > The PS is working with 15 volts out and the 3 fuses in the front are fine. > The 10 volt card checked OK in my spare repeater No 10 volts at all. > > Any ideas? > > Ben-W4WSM > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > >
