restoring old tv's

[DaveWM]

Just wondering. After messing about with my philco roundie and finding a few bad parts, anybody ever think of just replacing EVERY resistor and cap?

I mean on a PCB its very easy. I realize the in the RF section it "may" cause some issues depending on if its in a tuned circuit, but all the coupling an bypass caps, all the plate/screen/cathode resistors etc...

At least you would know its all at the base line values.

just thinking out loud. guess its a form of "restoration vs repairing".

I realize that shotgunning paper caps is the norm, but I was thinking shotgunning everything in sight that is readilly availble. Not that I plan to do it as it seems like a lot of effort, just wondering if anyone else has thought along these lines.

[Dave S]

Yep, it's been done.

Check out this wild story about how Hugo Holden restored an RCA 621 to better-than-new condition.

Can't say I'd ever go to that extreme myself, but you've got to hand it to the guy, that's pretty impressive!

[DaveWM]

WOW!!!

now that is a restoration!!!

[ctc17]

I try and keep as many original parts as possible, most of those old resistors and caps are american made. I have also created more problems for myself doing blanket changes and I enjoy the challenge of finding the specific fault.

[Phil Nelson]

We know that a resistor's value is critical in some circuits, but not so important in others. I once found a radio where a guy had replaced a 27K resistor with a 27-ohm resistor. Seems like a real boner -- 1/1000th the specified value! -- but replacing the resistor didn't change performance noticeably.

If a TV's design seems "on the edge," I'd feel like being more aggressive with resistors. My DuMont RA-103 seems so stable, I doubt a nuclear blast could make the picture bounce. On the other hand, when my restored Predicta had a relapse and I pulled the main PC board, I replaced just about resistor on it, saying "I never want to pull this danged board again!"

In the radio world, some boatanchor collectors get a kick out of stripping the chassis to bare metal, replating it, and going from there -- installing all new components except proprietary parts like coils & tuning capacitor. You could do this with a TV, as Hugo Holden did, but I call that remanufacturing rather than restoration. It seems more of a stunt, something you'd do once and then say, "Never again!" By the time you're finished, much of your original TV is parts in a junkbox, and you're watching something different.

Phil Nelson

[DaveWM]

yea I am not about to do it, just wanted to see what others thought.

[Dan Starnes]

I have thought about it, but have not done it. I would possibly go crazy at some point.

[bgadow]

This gets done a lot with Heathkits. People will strip them down and, using the original instructions/new parts, build them from scratch again.

Now, I have had daydreams of building a decent radio from scratch, but that would be the limit for me, I think. To do a tube color TV....I'm not sure if the reliablity gain would be enough to justify it. Components will still go bad, and you may even find that some of the replacements are no better than what you replaced. (just speculation there.)

[matt_s78mn]

Originally Posted by bgadow

This gets done a lot with Heathkits. People will strip them down and, using the original instructions/new parts, build them from scratch again.

What a great idea. I had never thought of doing something like that before but it sounds like fun.

[oldtvman]

resistors are passive components and unless they are burnt, it's usually not necessary to replace resistors. The best way as I stated again is to check voltages and make sure all power supplies are up to snuff. We used to call replacing everything shotguning and it was usually techs who didn't really know how to troubleshoot circuits.

[sampson159]

we used to have a guy named eppy back in the old days that would just replace everything in the circuit until he found the problem.i liked him,he was a really good guy but the work he made for himself!on the other hand,it was a good set when you got it back.everything was new!

[old_tv_nut]

Originally Posted by sampson159

we used to have a guy named eppy back in the old days that would just replace everything in the circuit until he found the problem.i liked him,he was a really good guy but the work he made for himself!on the other hand,it was a good set when you got it back.everything was new!

For a car, that was called a "gas-station tune-up."

[Dan Starnes]

Originally Posted by old_tv_nut

For a car, that was called a "gas-station tune-up."

Xactly,, takes all the troubleshooting out of it.

[Kalamazoo-DJ]

Originally Posted by DaveWM

Just wondering. After messing about with my philco roundie and finding a few bad parts, anybody ever think of just replacing EVERY resistor and cap?

I mean on a PCB its very easy. I realize the in the RF section it "may" cause some issues depending on if its in a tuned circuit, but all the coupling an bypass caps, all the plate/screen/cathode resistors etc...

At least you would know its all at the base line values.

just thinking out loud. guess its a form of "restoration vs repairing".

I realize that shotgunning paper caps is the norm, but I was thinking shotgunning everything in sight that is readilly availble. Not that I plan to do it as it seems like a lot of effort, just wondering if anyone else has thought along these lines.

mine have been done that way, but it takes a huge amount of time, a bit of cash and it leaves little to mess with, but still does not guarantee perfection such as my ctc9 still goes out of wack intermittently and a real pain to find now that its all new in there.

[oldtvman]

In the world of electronic techs, if you took the approach of simply replacing parts you were made fun of and sometimes yelled at by the boss. We were always taught to use prescribed troubleshooting skills to find the problems. It has always worked out good for me and saves a lot of time and money.