1966 GE PortaColor Restoration - Videokarma.org TV - Video

maxhifi · #1 10-28-2019, 08:13 PM

Quote:

Originally Posted by Dubis7

Okay, I traced the two ends of L34 and haven't had any luck. Everything has continuity so far. Any other direction?

Luck with what? What has continuity? Are you getting B+ when the set is on?

Dubis7 · #2 10-28-2019, 09:10 PM

Quote:

Originally Posted by maxhifi

Luck with what? What has continuity? Are you getting B+ when the set is on?

Sorry, should've been clearer. In tracing the line between L34 and the associated 100uF cap, there are no visible fuses and everything has continuity. All the diodes test good, and I run continuity tests on all the wires to see if one of them was meant to work as a fuse. If they are, then none are broken.

Right now the cord is locked into the back of the cabinet, so I haven't been able to run any tests to see where the B+ breakdown is. I'm going to guess I don't, though, since there's no life beyond the filament string. My next step is going to be freeing that cord so I can start doing voltage checks with the set on.

dieseljeep · #3 10-29-2019, 09:22 AM

Quote:

Originally Posted by Dubis7

Sorry, should've been clearer. In tracing the line between L34 and the associated 100uF cap, there are no visible fuses and everything has continuity. All the diodes test good, and I run continuity tests on all the wires to see if one of them was meant to work as a fuse. If they are, then none are broken.

Right now the cord is locked into the back of the cabinet, so I haven't been able to run any tests to see where the B+ breakdown is. I'm going to guess I don't, though, since there's no life beyond the filament string. My next step is going to be freeing that cord so I can start doing voltage checks with the set on.

The power cord interlock connector is held by a "C" clip, easy to remove. It's the earlier PortaColor chassis.
IIRC, The set has two power supplies, one half wave 140 volt source and one 240 volt, voltage doubler source. It has three power supply diodes and maybe two wire-wound resistors. The power supply is near the HV enclosure and there should be a fuse nearby, as well.