View Full Version : Zenith 29JC20 chassis with RCA test jig?


Tim
07-24-2018, 10:47 PM
I am planning to work on a Zenith 29JC20 for someone but I would prefer not to transport the entire set home. Has anyone connected this chassis to an RCA test jig? The RCA jig manual does not list the chassis. The CRT connection is no problem and I suppose I could figure out the yoke if needed but maybe someone already has?

Also wondering if any jumpers are needed for the convergence socket, such as the RCA chassis requires, so the convergence assy can stay mounted on the CRT in the cabinet.

Thanks for any thoughts.

zeno
07-25-2018, 07:09 AM
It will hook right up with the CRT adaptors & yoke.
I dont think the Zenith has it but many sets put electrolytic
& resistor for the vert output cathode on the board .
Thats the only thing you gotta watch.

73 Zeno:smoke:
LFOD !

Electronic M
07-25-2018, 01:51 PM
Dirty secret: The RCA test jigs were rebadged Telematic Jigs. If I had access to the books for my jig right now (I don't) and knew which model jig you've got I could read off the adapters you need. I don't have time to open my Zenith 29JC20 to confirm, but next week onwards I may swap the CRT on it (one in it takes ~20min to 2 hours depending on the number of days powered off to reach usable brightness)...IIRC the yoke or convergence plug does interlock the horizontal B+.

Tim
07-25-2018, 02:23 PM
Thanks Zeno and Tom. I did look in the RCA Jig manual and the 29JC20 chassis is not listed but later Zenith models are. I do not have the chassis yet so I can wait for whatever you find Tom. My Jig is a 10J106. I have used it successfully on RCA roundies.

oldtvman
07-25-2018, 03:06 PM
We used to put the sets up on carts and service them from the bottom access plate, no need to remove chassis.

old_coot88
07-25-2018, 10:10 PM
We used to put the sets up on carts and service them from the bottom access plate, no need to remove chassis.
We had rollaround service carts with carpeted tops for that purpose. Carpet protected the up-ended cabinet. Often had to slide the chassis back in addition to removing the service plate.

Tim Tress
11-22-2018, 04:06 PM
We would flip the Zenith color sets upside down, on a raised wooden platform with a carpeted top; two people were needed. With the bottom plate removed, most of the parts were accessible. I did prefer to pull the chassis for some repairs, such as replacing flybacks or electrolytic capacitors.