#46
|
||||
|
||||
Quote:
|
#47
|
||||
|
||||
Yep, filament is definitely lighting. Tube socket aside for a moment, do you think it would be a waste of time to shotgun the rest of the components on that board?
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#48
|
||||
|
||||
Quote:
[Edit: can you get at the bottom easily? Otherwise, a socket extender can be helpful if you have one.] |
#49
|
||||
|
||||
Give us all the voltages on pins of 6CG7 hor osc and afc. You can remove 6DQ5 hor out and the damper tube to measure it
|
#50
|
||||
|
||||
Thanks....give me a day or two and I'll get it back up on the bench. I have to repair my socket extender.....one of the long metal rods pulled right out of the sucker last time I used it
I've been running all of the tests with the 6DQ5 out. To do the diagnosis last time, I had the yoke and convergence board out of the set and plugged into the chassis and everything laid out on the bench so that I could move it around more easily.
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
Audiokarma |
#51
|
||||
|
||||
Jack Darr did a good writeup about servicing the Synchroguide circuit, if I can find that .pdf I'll post a link..
|
#52
|
||||
|
||||
Quote:
I have 3+ more older RCA's waiting after finishing two CTC16s where tube sockets looked normal but were definitely bad..
__________________
"When resistors increase in value, they're worthless" -Dave G |
#53
|
||||
|
||||
Tested resistances. Everything is perfectly in line, except pins 8 and 9. Measured from M1, I get about 8K. Measured from chassis ground, it jumps around (assuming because I'm not using a VTVM) in the range of 40-120 ohms. Should be zero ohms on both.
Since both pins are ground, are we looking at a bad tube socket?
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#54
|
||||
|
||||
OK, now jumper to ground pins 8-9 on your test socket and see what it reads, better yet, apply power. Not sure what M1 -is I'm' using the RCA schemo.
__________________
"When resistors increase in value, they're worthless" -Dave G |
#55
|
||||
|
||||
Quote:
One more thought - make sure your ohmmeter reads a solid zero when you short the leads together. |
Audiokarma |
#56
|
||||
|
||||
Sam's for the 11 can be found here: http://earlytelevision.org/pdf/rca_ctc11_sams_550_2.pdf
I don't see a M1 on it, but then again I did not take much time to carefully look... If socket pins, that are shown on the schematic as grounded, measure over an ohm to chassis, then either the ground path is bad, your meter has a problem, or the connection points are dirty. Suspect board to chassis ground connections, traces, and socket in that order.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#57
|
||||
|
||||
Why M1 (B+ rectifier)? Most resistance readings are taken from Chassis ground - using M1 as a reference for any DC or Ohms measurement will result in odd values - those doubler caps charge and discharge, giving odd values. Clip the negative lead to chassis, and measure to the pins....
Lower left of Page two on the Sams gives the instructions - common negative (Chassis).... Have you verified the resistances of the ground traces on the board to the chassis - measure the trace, not at the corner eyelets. Those eyelets are 90% of the problems with most RCAs. IIRC, you resoldered those early in the thread.
__________________
Brian USN RET (Avionics / Cal) CET- Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit! Last edited by Findm-Keepm; 01-10-2017 at 06:41 PM. |
#58
|
||||
|
||||
It's also where many of the resistance tests for that tube are taken from.
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
#59
|
||||
|
||||
Pin 8 and 9 to ground should measure close to zero - and you have resistance. Taken from Socket (above) or pins (below), they should both be close to zero.......I'd start there. Runs to the eyelets....simple trace. Assuming the solder connection is good - bigger the blob, better the job does not apply here - go for a clean, shiny fillet.
__________________
Brian USN RET (Avionics / Cal) CET- Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit! |
#60
|
||||
|
||||
Cleaned the snot out of the socket and ran my iron over the pins just for good measure. We're now down to 1 ohm, confirmed with both the Snap On meter I always use, and my Jackson Tele-Volter that I rebuilt.
Time to try this again.....
__________________
"Restoring a tube TV is like going to war. A color one is like a land war in Asia." |
Audiokarma |
|
|