View Full Version : 1950 Motorola update


suede
11-13-2009, 06:10 PM
So i finally got my chassis out of my cabinet. Its surprisingly clean, looks good. I did notice a busted 25l6 gt tube, so i replaced it. Plugged it in and.. nothing. All tubes light up, including the back of the crt, but no snow, no light, no nothing on the face of the crt. No idea of where this newbie should go from here.

http://img297.imageshack.us/img297/2529/cars016.th.jpg (http://img297.imageshack.us/i/cars016.jpg/)

URL=http://img697.imageshack.us/i/cars017.jpg/]http://img697.imageshack.us/img697/2714/cars017.th.jpg[/URL]

bgadow
11-15-2009, 09:45 PM
To start, have any capacitors been changed? Or is this in "as-found" condition? If the electrolytic caps haven't been changed I would start there. Beyond that...I only come up with more questions. We can work you through it, though.

Phil Nelson
11-15-2009, 10:01 PM
The power supply is the place to start, and electrolytic capacitors in the p-s are Job Number One. Here is basic advice about replacing capacitors if you haven't done that before:

http://antiqueradio.org/recap.htm

You have the schematic, right? It not only shows how things are connected, but usually has a voltage chart that's very helpful in diagnosing problems like this. Without a schematic, you're shooting in the dark.

Phil Nelson