Hi Everyone!

My Saba Freudenstadt 7 has stopped working. I saw a flash from under the chassis and it will not power up. Do you think there is a short? How can I test?

If the old capacitors have not been replaced there is a good chance that one or more have shorted and taken out a few components, maybe even the transformer. If the fuse is blown, DON'T replace it. The problem is still there.

With a meter.....

Seriously, do you have a multi-meter and a copy of the schematic? There are several ways of approaching this, but I would probably start by disconnecting the filter caps and checking the DC resistance of the various power transformer windings. A careful visual inspection may give you some clues also.

visual inspection is a good place to start.
Unplug the set, , and remove it from its enclosure and look for something that looks freshly burnt. Also use your sense of smell.

I bet you will find the problem quickly...bruce

The radio was recently restored and everything looks clean if not new. The capacitors all look new. Some resistors have Saba written on them and might be originals. It passed the sniff test, nothing burnt.

That flash was *something* vaporizing. I have been doing electronics work for 40 years, never once has something gone "bang" without leaving some sort of trace. I would suggest another careful inspection, there *will* be some indication.

Brett

You don't think it could just have been the auto-thyristor in the flux capacitance circuit? Were you going 88mph when this happened?

(Sorry... ducking my head...)

Flash may have been too strong a word. It was more like a blinking. Nothing seems to be burned. Could it have been the transformer? There is a coil on the bottom of the chassis.

If you have not found anything obviously burned up or incompetent wiring, and the transformer windings check out OK ohmically and voltage wise all the way down the voltage divider network and you used some deoxit and exercised the switches many times, my attention would turn to a burned out tube. Usually pretty far down on the list, but pretty easy to check filament continuity.

Is the fuse mounted in an open clip? That will give a flash, and fuses sometimes just blow due to a power spike, or old age. A bad pilot lamp can sometimes fail and short at the same time, taking out a fuse, so look at the lamps.
Don