View Full Version : RCA 6T65 problem


7"estatdef
11-19-2012, 07:02 AM
Have had this set up and running for about 10yrs now and has a few problems along the way. All in all it has done well for a 62yr old set. When I serviced it all the paper/electrolytic caps, micas as needed and resistors as needed and weak tubes got replaced.
The issue now is low anode voltage to the CRT/no picture. I've got about 2KV. Have swapped out the 1B3,6W4,and the 6BG6. All the voltages look pretty good and the HO plate is running cool, no red angry plate.
Open to sage advise and a copy of the sam's for it, chassis KCS-47.
Tnx much
Terry

Zenith26kc20
11-19-2012, 08:46 AM
Turn all the lights in the room out and slowly advance the brightness control from minimum and look to see if the raster is "keystoned". I just did a Zenith with a shorted yoke that had very low high voltage and the raster was keystoned and very dim and would bloom out at almost no brightness at all.

bandersen
11-19-2012, 09:53 AM
I've parted out a couple KCS-47 chassis and have a bunch of spare parts. So if it does turn out to be a shorted yoke or another defective component, please let me know.

7"estatdef
11-19-2012, 10:28 AM
I should mention that before it went black for a week or so the picture would go dim and then it would go back to it's normal brightness. At first I thought it may have problem with the cathode or grid circuit of the crt. That was before I measured the anode.
Did swap the 16GP4 but that was to no avail.
The Sam's is 113-7. I could use just voltage and resistance measures page if someone would be nice enough to scan it.
Tnx Bob for your offer, could use a width coil, a flyback and a vert osc transformer if you have any of these to spare
Tnx Guys
Terry

DavidGoncalv
11-22-2012, 12:22 AM
Check resistance of Hv output series resistor.

7"estatdef
11-23-2012, 04:34 PM
Good Idea but isn't one on my schematic.
Terry

bandersen
11-23-2012, 05:04 PM
...Tnx Bob for your offer, could use a width coil, a flyback and a vert osc transformer if you have any of these to spare

Yes, I think I can spare those. I'll try to dig them out over the weekend.

7"estatdef
11-25-2012, 11:09 PM
Tnx Much Bob!
In no rush at all
Terry

7"estatdef
12-17-2012, 12:51 PM
Got it working! It was something stupid of course. Bad connection at the SG of the 6BG6. Resolder it and I'm back in business.
Tnx for your help
Terry