New Member With A Vintage TV

[VA561]

I would say my soldering skills are good. Reading schematics is average. Thanks for the warnings about being zapped. I will use extreme caution. Although it may not look like it, the brightness is turned all the way down. I think it is the cell phone camera I am using. I will start replacing all of the paper capacitors and continue from there. With the help of everyone here I'm sure I will get this old tv running again.

[DaveWM]

yep, 9 times out of 10 the paper caps will get it going, keep us posted.

[nasadowsk]

Basic TV safety (maybe we should have sticky for this, guys?)

* If it's not line isolated - use an isolation transformer!

* Watch the CRT - the neck is fragile and old CRTs don't have the safety feature of new ones - glass can really fly if they pop.

* The high voltage 'suction cup' and horizontal sweep section - nasty when on, can hold a bad charge when off. Once unplugged, a screwdriver grounded to the chassis can be slipped under there, it'll make a little *pop* then it's safer. Touch under the cup and any other points in the HV box before going in there.

* NEVER measure the horizontal output tube plate voltage - there's a multi thousand volt pulse present on it.

* Don't try to look in the dark to see if the 1B3 lights up. It doesn't. Yours is fine.

* The vertical section may operate at elevated voltages, also.

* Be wary of electrolytic cans mounted on insulating wafer mounts - they may be at higher than ground voltage. Maybe they had a cover, maybe they didn't.

* Some CRTs have metal cones. The cone will be at high voltage while the set is operating. Even with an insulation apron over it, avoid touching.

* The insulation on the HV lead, and in the HV box won't prevent a shock. Just don't touch those areas!

* The 'lower' B+ voltages can have upwards of 1/2 an amp to back them up! They're just as nasty as the high voltage.

As always, the safest route is to turn off, unplug, and touch a grounded screwdriver lightly around the areas where you'll be working. Some sets can work with the horizontal output tube pulled out (or the fuse removed), but not all. This reduces the high voltage danger from the sweep sections greatly.

[VA561]

Thanks for all of those safety tips. Especially good to know for someone who is not an experienced tv repair person. I am going to print that page so that I can look it over before I remove the back cover.

[VA561]

The '52 Philco I am attempting to fix is model #52-T2151. I found a service/repair guide for sale but it is for a 52-T2151-L. Could iI still use this service guide? I don't know what the L is for.

[jr_tech]

I think that Philco used "L" for the light oak cabinets... I would guess that the chassis is the same.
jr
1952 brochure:
http://www.tvhistory.tv/1952-Philco-Brochure1.jpg

Update...I dug out an old Sams Photofact listing and they show 2 listings for the model:
52-T2151 (ch 41,D1,A) .... set 171, folder #9
52-T2151 (ch 71,G1)....set 179, folder #9
No mention of "L" (light oak blond), "M" (mahogany) or "W" (walnut) however, in the index.
Do you see a chassis # on the label or stamped on the chassis?
jr

[PredictaNoob]

Wow! Great basic stuff Nasadowsk, thank you for posting it. I too printed it out and taped it to the wall in front of me at my work station. Sometimes I get into what I am doing, so much, that I can forget basic safety. A couple of thousand volt jolt can instantly refresh my memory, but I'd really like to avoid that whole death thing for now...

[RitchieMars]

I have a feeling that that Philco may turn out pretty nice for you based on what I'm seeing so far. At least you've got something bright coming up on the screen, unlike the sea of dim grey lines I've gotten on my Zenith. We're also in the same boat far as the audio department goes... I wonder if there's a trend or pattern to the way that television sets age, and what components stop working along the way? Undeniably, the thing I hear the most often is those old capacitors. I guess it's sort of universal, be it radio, television or anything over 50 years old with a hand-wired chassis.

[VA561]

Here are some pictures of the split chassis. Looks like I will be dealing with a lot of capacitors. Maybe it wont be as difficult as it looks.capacitor1.jpg

capacitor2.jpg

capacitor3.jpg

capacitor4.jpg

[Phil Nelson]

If those diodes are intended to replace the big green selenium rectifiers, I'd make sure that the old rectifiers are taken completely out of the circuit. (Don't leave them wired in parallel with new diodes, in other words.) Hard to see exactly what's going on in that third photo.

Phil Nelson

[jr_tech]

Originally Posted by Phil Nelson

If those diodes are intended to replace the big green selenium rectifiers, I'd make sure that the old rectifiers are taken completely out of the circuit. (Don't leave them wired in parallel with new diodes, in other words.) Hard to see exactly what's going on in that third photo.

Phil Nelson

Most people also install some resistors in series with the diodes, so that the B+ voltage ends up being the same as it was when the seleniums were used.
Now people might throw rocks at me for this... but what about mounting the new diodes and proper dropping resistors on a terminal strip under the chassis, next to the fuse and eliminating the "tacked on" selenium housing/exposed wiring?

jr

[bandersen]

I like that split chassis. Much nicer than lugging around one huge chassis. I think you'll find that once you start replacing those big old caps with modern, smaller ones, it will become less cramped and easier to work on.

Good luck.
Bob