View Full Version : making progress? on my '50 motorola 12T3


jbivy
05-11-2011, 01:49 AM
In a nut shell, ive mostly recapped this old girl. Now its come down to the cans, well thats my problem. Id seen one taken apart before and it had individual caps in it. I replaced the first one that had only two wires to it and one value written on it, relocated that to the far back of the chassis as both wires were right there, so it seemed odd to keep it in the stock location. Then i drilled the rivets out to the another which had four values written on it, thinking it would just have individual caps in it and yes, i now realize how dumb i was when i opened it up.

Well im unsure of where to go from here now. The schematics are pretty much greek to me. Ive marked the wires that went to each terminal, but.. No idea where they DO go. Ive an uncle who repaired tv sets in the 60s, im debating on bribing him with a bottle of scotch to help me with this puzzle.

Any idea of where i should go from here?

http://img689.imageshack.us/img689/3954/tvsetsandradios016.jpg (http://imageshack.us/photo/my-images/689/tvsetsandradios016.jpg/)

David Roper
05-11-2011, 02:07 AM
You'll be much better off learning to read the schematic. Mistakes happen, so it puts you in a bad spot if you can't verify the way you have things connected against the way they're drawn.

Winky Dink
05-11-2011, 02:22 AM
I have copious documentation of the 12T2/12T3. Sams, Rider's, and a gazillion photos of the chassis. I'm too sleepy to give a rational response right now, but here's a link to a Picasaweb album, and I'll follow up with specific information as soon as I can.

https://picasaweb.google.com/coldrb/Motorola12T21950?feat=directlink

-Winky

bandersen
05-11-2011, 03:11 AM
Is that the TS-53 chassis ? I have the one from my 12K2 up on the bench right now, but haven't touched anything yet.

Would some reference photos of it help you ?

jbivy
05-11-2011, 06:11 AM
I have copious documentation of the 12T2/12T3. Sams, Rider's, and a gazillion photos of the chassis. I'm too sleepy to give a rational response right now, but here's a link to a Picasaweb album, and I'll follow up with specific information as soon as I can.

https://picasaweb.google.com/coldrb/Motorola12T21950?feat=directlink

-Winky

Well Winky,

Im working from just a sams photofact, which doesnt get into much detail. Thats why im unsure of where to hook up the new capacitors. Id greatly appreciate whatever help you could give, photos, specs, etc.

Ive bitten off far more than I can chew with this old beast. My experience to date has been opening non working radios, buying the caps off ebay, replacing those and the wiring. So this tv is still pure magic to me. Though I suppose you have to start from somewhere, but ive learned quite a bit more since ive started reading all the threads here.

and Bandersen, well all i know is that this says its the 12t3 chassis and it matches the picture on the sams, a small table top model.

Winky Dink
05-11-2011, 09:57 AM
Give me some time (one or two days) to go through my notes and photos. I had less experience than you when I started recapping the TV, so I think I'll be able to get you the information you need.

Winky Dink
05-11-2011, 05:19 PM
Here's a starting point:
https://picasaweb.google.com/coldrb/MotorolaTS53Cans?feat=directlink

The photos show the connections from the positive terminals of C1, C2, and C3. I had fits when I was doing the cans because I didn't know that the symbols (square, triangle, etc) showed which terminal went to which capacitor.

The last photo is an orientation grid which I can use to help you locate the areas in the photos, if need be. These are mostly original-condition photos, before changing any of the components.

How much of the Sams folder do you have? I have an original 16-page folder and can post whatever you need.

jbivy
05-11-2011, 08:37 PM
Ive the whole sams, im just not understanding it. It was helpfull when i replacing the capacitors, showing the values and making sure that i didnt make any wiring mistakes.

But these cans are throwing me for a loop. Im going to see if i can find something online to show me how to read schematics, so then maybe i can figure out where the new caps go and which wires to use.

Winky Dink
05-11-2011, 09:43 PM
Listen to the voice of inexperience. The above link shows each positive-terminal connection for each of the electrolytics in C1,2,3. When you find these connecting points you can trace the wire back to the original location of the cans.

I learned to read schematics by going back and forth between the schematic and the real-life wiring and components. Most of the difficulty is that the schematic does not reflect the actual position of components and often does not show the actual configuration of the wiring. I found it helpful to stick labels each component. Your first step will be to find the eight electrolytics which are scattered all over the schematic. Just imagine that each cap is a Waldo and play "Where's Waldo."

If you get too frustrated and you're going to throw the set out of the window, please save the focus coil and deflection yoke for me.
- Winky

kramden66
05-11-2011, 11:26 PM
the electrolytic can / cans have the values and voltages , so looking at the parts list in the sams you can figure out what can it is , and then the schematic should show what electrolytic is c1 , c2 , etc , also the schematic would show c2 A and value , c2 B and value , like stated you can follow the wire and see where it goes in the set and then by looking at the schematic you'll be able to figure out what wire is what value and voltage , take your time and you will figure it out , make notes too on a paper so you don't forget

mike

jbivy
05-12-2011, 12:34 AM
well if my hair wasnt buzzed off, id be tearing it out, but tomorrow ill be fresh and try my best to install the new caps.

Though im uncertain of my crt's condition and if it is bad..well then im going to be evil and look for a b&w plastic set that can be fit into this and give away the original parts that are still good to restorers. The filament lit up when it was installed in the chassis, the "flash getter" cup is still metal colored and hasnt turned white. So i THINK its still under vacuum.

bandersen
05-12-2011, 11:07 PM
I just starting working on mine and I have a question maybe you or Winky Dink can answer.

C98 is supposed to be a 0.03 going from a flyback winding to ground. The other side of that winding goes to the chassis. That's the little green wire I've circled.

However, on mine the flyback lug that C98 goes to has a wire that snakes around and is soldered right to the chassis

So C98 is really going between ground and the chassis on my set or the flyback winding is a dead short :scratch2:


http://www.bobandersen.com/images/motorola%2012K2/C98-02.jpg

http://www.bobandersen.com/images/motorola%2012K2/C98-01.jpg

kramden66
05-12-2011, 11:36 PM
if the crt lights you shoulde be able to get something out of it even if it needs a brightener , what is the crt number ? ... don't give up on it and put a more modern set in it

mike

Winky Dink
05-13-2011, 12:54 AM
My C98 is wired exactly as you describe. One lead goes to the vert linearity control. The other goes to a lug on the flyback frame but has no apparent connection to the flyback. Instead, a green-insulated wire from the lug snakes behind a coil, comes out the other side and is soldered to the chassis. Here's an old picture:
https://picasaweb.google.com/lh/photo/S1mqvXh2Cj70ez3HviRiGg?feat=directlink

-Winky

jbivy
05-13-2011, 01:23 AM
if the crt lights you shoulde be able to get something out of it even if it needs a brightener , what is the crt number ? ... don't give up on it and put a more modern set in it

mike


12lp4a, though i read that a few others can be made to work.

bandersen
05-13-2011, 01:24 AM
if the crt lights you shoulde be able to get something out of it even if it needs a brightener , what is the crt number ? ... don't give up on it and put a more modern set in it

mike

Yes, please don't give up yet. I'm starting work on mine right now and can trace out any wiring you may have questions about.

My C98 is wired exactly as you describe. One lead goes to the vert linearity control. The other goes to a lug on the flyback frame but has no apparent connection to the flyback. Instead, a green-insulated wire from the lug snakes behind a coil, comes out the other side and is soldered to the chassis. Here's an old picture:
https://picasaweb.google.com/lh/photo/S1mqvXh2Cj70ez3HviRiGg?feat=directlink

-Winky

Thanks! Weird how both Riders and Sams show a 33 ohm flyback winding attached to that cap.

kramden66
05-13-2011, 08:57 AM
12LP4 is not uncommon but not as easy to find as 10BP4 , still they are out there.


mike

jbivy
06-01-2011, 07:40 AM
well after another trial and error (realizing a few mistakes i did make), ive made the decision to call in my uncle for help, who repaired tv sets in the 60s.

Truth be told, he offered to help, after he saw this old girl tore apart on my kitchen table. He read over the schematics and what Winky Dink supplied, he thinks between us two, we can get this old girl to work again.