View Full Version : Tubes light up, but I lost sound and picture


Captain Video
11-01-2015, 10:31 PM
I have this 11 inch screen set, an early 1960's Invictus TV ( Brazilian brand ). It is an all - tube set. I haven't turned it on for months, maybe some four months, maybe more. Today I decided it was time to put it to work, it was running for something like two hours, and then suddenly the screen went dark and I also lost sound. I looked inside and the tubes ( including the CRT neck ) are lighting up, so what might be wrong with this thing?

rca2000
11-01-2015, 10:44 PM
Likely a loss of B+ supply, shorted diode and open fuse/resistor, or a cap that decided to open and kill the b+

Electronic M
11-01-2015, 10:59 PM
Likely a loss of B+ supply, shorted diode and open fuse/resistor, or a cap that decided to open and kill the b+

Unless it is a doubler cap, it would have to short NOT open to kill the B+.....Open would just cause lots of hum.

rca2000
11-01-2015, 11:03 PM
Unless it is a doubler cap, it would have to short NOT open to kill the B+.....Open would just cause lots of hum.

But the result of a totally open cap would be VERY LOW B+===along with terrific him...MAYBE enough to stop ckts. from running...

kramden66
11-05-2015, 08:38 PM
Maybe it is the rectifier tube. The 5u4 or whatever it uses. Check tubes first before pulling the set apart

rca2000
11-05-2015, 08:42 PM
NOT likely ANY 11 inch set uses a tube LV rect.

Nearly SURE that is a hot set.

kramden66
11-06-2015, 07:49 PM
Selenium rectifiers?

Captain Video
11-06-2015, 09:25 PM
It was a BIG capacitor that failed... the tech that repaired the TV for me said that this capacitor was there on the set the day it left the factory, more than 50 years ago.

Captain Video
11-07-2015, 08:02 PM
Made this little video of the TV after I brought it back home:

https://www.youtube.com/watch?v=cXwFq7c7SCs