Cleaning circuit board based chassis?

[RetroHacker]

Well, I'm back... I've been doing my best to get myself organized enough to be able to get back into my hobbies of collecting/fixing old TV's and old computers. I finally got my workbench clean and organized, and I'm ready to start restoring a set I've been wanting to get going for a long time. It's a 60's GE set, 21" 110 degree tube, with a really wacky 9"x21" oval speaker. It plays great, gets a sharp picture, and tuning is OK. The tube is good and strong. Only problem is that the picture is smashed to about 1/2 the proper height, and the whole thing needs a thorough cleaning.

The chassis is a metal frame around a large printed circuit board, and it's covered in grime, dirt and more grime. The sets I've worked on and cleaned have been metal chassis types. What's the best way to clean a board like this? It appears to be phenolic, but might be an early fiberglass type board, I'm not sure. It's hard to tell under the crud. I can't even read the values on the resistors this thing is so filthy.

Also, in general, what other advice on cleaning sets do people have? I've been using the time consuming method of carefully cleaning a metal type chassis with paper towels and alcohol/windex. Most of the time I wind up replacing all the paper capacitors, and the rest of the components I typically leave alone. But in this case, with the circuit board chassis, I want to clean off resistors so I can read them, but not so that I clean the values off. Likewise with other parts.

Tubes I also typically leave alone unless they're completely filthy, since while the glass polishes to a nice clean shine with Windex, the numbers wipe off too easily. These are completely filthy. Any ideas? What about picture tubes? What can be used to clean a picture tube without cleaning off the aquadag coating?

What about other components? Wire? I swear this set looks like it was stored in a barn for years.

-Ian

[Eric H]

You might take a look at this thread: http://www.audiokarma.org/forums/sho...d.php?t=140210

I cleaned that chassis in the bathtub with some spray cleaner and then hosed it off with the shower.

You have to use a little discretion and keep water away from the flyback and power transformer, also paper labels should be covered or temporarily removed first.

Most late 50's sets used plastic coil forms and molded caps so they are pretty water resistant.

[RetroHacker]

Nice work on that set Eric. I'll have to see what kind of cleaners I can find around here. That "Blue Beast" stuff you mention sounds great, but I'll have to find something similar. Is it a degreaser? Floor cleaner? Is it anything like say, Simple Green? 409? I'll check at the store on the way home from work and see what I can find that might work. All I've got is the basic array of home surface cleaners, nothing too powerful. I need something that'll take the grime off but not dissolve bakelite, phenolic or resistors. BTW - how _did_ you find out that "Blue Beast" dissolves bakelite? I didn't think there was much that could. Bakelite won't even melt.

This is a 60's set, so it probably uses paper coil forms. I'll go over the chassis carefully first and tape some plastic over anything that I don't want to risk getting wet. I've never tried hosing down a TV chassis before (although I've done it with computer circuit boards. Those you can put in a dishwasher...).

Anyone have any idea on tubes? A couple of these are going to have to be cleaned, they've got enough fuzz to be approaching a fire hazard. Now, I could just scrub them and forget about the numbers, but I'd like to keep them on. Maybe if I try soaking them in plain water? Also, another thing I have often wondered - If you _do_ rub the numbers off a tube, how can you mark it so that you know what it is? I've thought about just writing the numbers back on with a Sharpie pen, but what happens when it gets hot?

Tonight on the way home I'm going to stop by the library and get the schematic. (I got it once already, when I found the set three years ago, but managed to lose it.) This set has a few of those blasted black beauty/bumblebee capacitors, a couple of which don't make sense when I translate the color code (.00033 at 9400 volts?!?). Fortunately the library has photofacts (Sam's 483-1, GE U4 chassis, in case you were curious) and a photocopier that does 11x17.

-Ian

[bgadow]

Originally Posted by RetroHacker

Anyone have any idea on tubes? A couple of these are going to have to be cleaned, they've got enough fuzz to be approaching a fire hazard. Now, I could just scrub them and forget about the numbers, but I'd like to keep them on. Maybe if I try soaking them in plain water? Also, another thing I have often wondered - If you _do_ rub the numbers off a tube, how can you mark it so that you know what it is? I've thought about just writing the numbers back on with a Sharpie pen, but what happens when it gets hot?

-Ian

In many cases the tube numbers are put on with a different type of paint than the other information so that even if you wipe them clean the number will remain. Using a sharpie will be fine, though. The heat won't bother it. You could also use a paper label, though they don't age as well. Start with plain water on the tubes and if that just won't cut it you can move up to dishwashing detergent, then maybe windex. Most of the grime in old sets seems to be either tobacco residue or kitchen grease. The tobacco is probably the tougher of the two; I've used a strong industrial cleaner on some parts and it cuts the crud instantly. I've never bathed a full chassis, though. Guess I'm just not that picky.

Story: there was an older couple in the neighborhood that I didn't know. They grew sickly and moved into assisted living. I was then given all the electronics in the house, which was quite a bit as the man had been a cb/scanner hobbyist. The housekeeping, sadly, was dreadful. Everything was covered in a brownish/yellow film, and I mean everything. Their main TV (nice mid-80s GE console, the only thing I didn't get) was so covered that you couldn't really see the screen. Terrible smell, which I can still conjur up if I think about it. Ugh! Anyway, the film effectively shorted out all of the solid state electronics. They were all dead. The older tube stuff (a 19" hybrid color GE & an 21" bw Admiral portable) worked like new despite the grime.

[Tube TV]

Castrol super clean is great but it will also eat paint .
I normally use really hot water and a paint brush and a tooth brush , this usually gets most of it . then the super clean will take of the rest .
castrol super clean really fixes cigarette smoke and cooking grease .
it can also be diluted with water and it will be easier on the paint ,,, resistors ect .