Be sure to check the string of 6.8 meg resistors in the HV supply. Those were a problem for changing value.

The more I see the more I kick my self for not making an offer when I had the chance...I did not want to try to make a new offer-up account at work.

Guys,
I've scanned the Riders info on this TV. It's from Riders TV 1 pages 44 thru 75. I then enlarged the Schematic and Wiring Diagrams and made separate files for those whose size is 36x24 for us old geezers.

I've uploaded them on Dropbox.

The Manual is about 12megs and the Schematic and Wiring Diagram are about 1meg each.

https://www.dropbox.com/s/awm0knizur...anual.pdf?dl=0

https://www.dropbox.com/s/52cxfm9kln...36x24.pdf?dl=0

https://www.dropbox.com/s/ajfa53b9r9...36x24.pdf?dl=0

Looks like there's been some repairs there already. But I agree. A problem area with 621TS's.:smoke:

I meant it the other way around! Subsituting a PM ion trap for the EM ion trap and using a resistor in its place. :scratch2:

Yes, the 7DP4's were rebuildable. I have a Dunbar rebuild in mine, couldn't have seen many hours either since it tests like brand new. That's in my blonde model, I still need to pick up the mahogany one I won out of Connecticut recently.

Just a quick update. I ordered what I need from Just Radios, Digikey, and eBay. Tomorrow I'll enlarge the schematic and Wiring Diagram/Parts Placement drawing.

I got the schematic and Wiring/Parts Placement Diagram enlarged to 24 x 36. Just right!

I then started to work on the chassis. It is bit grimy and it has a layer of white corrosion all over. I think the plating did its job! To clean the chassis right, I decided to pull what I could off the chassis.

I pulled the yoke, the big resistor in the HV cage, HV cage, flyback, and HV rectifier tube and mount, and the resistor cage.

http://i1060.photobucket.com/albums/...pse3512l58.jpg

The big resistor had opened some tome ago and was replaced by 2 10K 20W resistors.
http://i1060.photobucket.com/albums/...ps7z6hruzq.jpg

Here is a picture of the bottom of the socket from the 1b3GT HV rectifier tube.
http://i1060.photobucket.com/albums/...psfizvksz4.jpg

While removing the resistor heatsink cage I found a wire that had barely been soldered on to one the resistor's terminals!
http://i1060.photobucket.com/albums/...psbfr5lf4z.jpg

I'll have more pics later. Lots came off the chassis.

Hey Crist, if you look closely it almost looks like they were soldered correctly at some point in time but the resistor had gotten so hot the solder has run down and has formed a drip on the bottom end of the terminal.

Gregb

Yeah, I can see where you'd think that. But the terminals are shaped like that! I have no reason why.

Here is a picture of the chassis as of right now. I'm going to install the yoke support so when I work underneath, it'll sit on the support and protect the IF Cans. I also cleaned and masked off the sockets to protect them while cleaning.

http://i1060.photobucket.com/albums/...pskzwgpoju.jpg

Here is a close up of the area where the support was screwed to the chassis. It is a good indicator of how dirty the chassis is.

http://i1060.photobucket.com/albums/...psdaim5bdj.jpg

I started on cleaning the chassis. I'm using a green colored cleaner that the wife uses as a general purpose cleaner, and a fine grit Scotch-Brite pad. Then I followed it up using the cleaner and 000 steel wool. Then a wiping down using WD-40. Cleaned up nice.

Anybody know the name of the stuff that you wipe on and it protects the bare metal?

I've got my work cut out for me for the rest of the day.

http://i1060.photobucket.com/albums/...psytbly3yq.jpg

I use Boeshield on bare metal

Steel wool can work havoc if the fine wires get into things. Inspect closely and be sure they're not in there.

10-4