77 sylvania
 

I can't find the chassis number unless its the real long one E4000....

anyway assy in mexico,has the 3 main boards, does NOT use the loose coupled power tranny and big motor run cap, instead has a SS regulator (I presume, its next to the HOT).

Two issues

vert kind of unstable, will colapse for a fraction of a second at times (I dont leave it alone and will not use it until i resolve as I do not want to burn the 25vdmp22.

second, looks like a yellow stain on parts of the screen (pls no jokes), I assume its a purity issue as when I went to set it up I did not get perfect red. in the same area.

However I was at a loss on how to set it up for purity. It seems like the horz yoke is not designed to be moved fore and aft and has no provisions for tilting etc. to adj. the purity rings are hard to adj since they are right up against the convergence board. they are current both set at 12:00. I did try moving them but was not able to get it any better, but I was limited in what I could do since I was fighting the conv board placement.

this one is in a very simple cabinet, with twist on legs. Clean by 1970's standards, I am guessing a low end set (cabinet wise).

pics,

the vert is still jumpy, I pulled the deflection board, reflowed some iffy looking solder (really not bad) including the socket for the yoke plug.

tested a few e caps since I had it off, one was a bit weak (power factor of about 35, again not bad but since I had it out to test I replaced it). reflowed some solder around the ground points (4 corners of pcb) cleaned the chassis at those points as well.

put it all back and it still is jumpy. intermittant jumpy that is, it will be fine for a while then kinda jump up from the bottom, not roll just shrink from the bottom a bit, then snap back.

I did reset all the transistors (sockets), but left the IC's alone, they where in real tight and I did not want to break anything.

guess I will pull it again and try checking some more caps. or maybe try some freeze mist to see what is going on.

E40 sounds right for the time - Sams 1620.

Dave,

What is the "power factor" you refer to - and how do you test it?

I've heard of value, ESR, leakage, and dielectric absorption tests for e caps, but this is the first I've heard of power factor.

Cheers,

that is an e 40 chassis.decent set,not quite as good as the 41,45,48.still pretty good.you have to loosen collar around yoke and move convergence board also to get purity.very easy.may have to degauss first.my mother bought a new set just like this.9 years later,she sold and bought a new xl100.worstset she ever had.dim picture,many service issues.i got her a e-45.she used it until i bought her the first 36 inch flat crt toshiba.that 45 is in her bedroom as a spare.still playing and still looking sharp!

I use an old heatkit condenser check (uses an eye tube, and a balanced bridge cirsuit for check caps) good of vintage gear esp leakage test at rated voltage, but can not check caps in circuit. there is a "power factor" adjustment, you turn to null the eye tube, which I think is about the same as ESR.

Aw geez, now I gotta buy anudder piece of equipment. Jes' when you think you have everything.....

Thanks! I've got some old Heath stuff - I'll have to see what I've got stashed away. I may have one of them varmits. Probably similar to my Sprague tester's eye tube checks - some kind of reactance vs value check.

Cheers,

I think I may have found the vert prob, after going thru every cap (all good) I finally did a swap on one of the vert out transistors, but now the stupid converter box is on the fritiz so I cant get a signal to check it out on. I cant believe what pure junk these DTV boxes are, this is the second one that went out, less than a year old. I have other video RF sources, but it will have to wait for a bit.

I did a quick check last nite and it looked fixed, so I was going to check again this am.

good job.those vertical transistors can have dirty socket issues.had more than a few.post more pics.the crt looks sharp and bright.

Watch out for the vertical controls. I have replaced many of them for the problems you describe.

the little pots on the back of the pcb? should I try an test them in circuit?

I have cleaned the transistor sockets, and the serv switch.

I guess the smart thing to do would be to touch those pots when it acts up...

tried it again, vert is rock solid, before it was sort of like a mild foldover on the bottom, then some shrink from the bottom, and the occasional wink out to no vert at all.

I may reinstall that transistor to see if that really is the prob. I also have a transistor tester (checks beta with large meter readout) just to see if it test any different, that is if I confirm it is the problem.

Put it on the transistor analyzer (eico 685) could not get it to calibrate, squeezing the transistor and all of a sudden it would deflect full. Def a mechanical defect in the junction, so I will be tossing this one.

heat does the same thing, it would open and close based on holding a hear source to the transistor. I wanted to make sure it was not my alligator clips on the leads that were causing the issue (the good transistor did not have any issues with the leads).