Starting work on the Sylvania 7140M

[Eric H]

This is the set I won at a local auction a month or so ago.

First thing I wanted to do is see how well the CRT held up, it hasn't been tested for a month so after pulling the chassis I hooked it up to the B&K 466, it didn't shoot up immediately to good, it took maybe 10-15 seconds but it ultimately went up to the top of the scale in less than a minute so i'd say it's pretty good!

Next, after removing the CRT from the chassis I wanted to clean off the heavy Cadmium Oxide crud, this stuff is highly irritating and very toxic.
I put down paper towels and sprayed it with cleaner, most of it was so loose and dusty it just rinsed right off, a toothbrush took care of the rest.

I pulled all the tubes and put them in a box to clean and test later.

I had noticed from looking at the schematic that this set used a very unusual set of tubes to rectify the high voltage, something I've never seen before in a set this old, it uses a pair of 5642 rectifier tubes.

I had to look those up because I had no idea what they were, turns out they are very small tubes that are soldered in place on the back of what I think is the flyback, I didn't take it far enough apart to see what that looks like.

I'll take the chassis to work to clean the rest of it off, it's just regular dirt that's left and the chassis seems to be very nice underneath it all.