...completely and safely dry out a CRT TV mainboard that has become soaking wet, through washing, rain inundation, flooding, or otherwise? I have two boards that will need thorough drying and I am worried most about the flybacks shorting. I seem to recall being told to put them in the oven at the lowest setting (150 degrees?) but I don't remember for how long...or if I should even try it. What do you guys do when a board needs a serious cleaning and drying, when the leaf blower and toothbrush just won't do?

hang em up and let em dry! I soak boards all the time for repair. you just have to make sure they are completely dry before using them. I usually use air from an air compressor to get the excess water off then let it dry on a hanger for a while (at least 24 hours).

A 24-hour air dry will be sufficient for the flyback to be okay? I remember having rinsed a projection set's mainboard once and waiting about three days, and the flyback wouldn't engage afterward...which is why I'm trigger-shy to do it again. :worried:

I use an electric leaf blower for a good few minutes to remove the excess water.

I have used lamps & hair dries to speed up drying.
Air compressor works good BUT once I was blowing out
a chassis & a coil snapped off, looked like a wire guided
missile shooting across the shop.
For small boards ive soaked them down with 91%
isopropyl alcohol. Takes the water away & drys fast.


73 Zeno

...

Thanks, guys! I have removed the mainboards and hosed them down gently, hit them with the leaf blower, then hung to dry for a few days. Both would be considered modern; a 1998 RCA 32-inch stereo monitor and a 2005 RCA 20F512T 'TruFlat' set.

Time is the best method.

Years ago, a customer brought in a 25" Magnavox set to me that he had found in a creek bed near his home. At the time, it was a fairly new set (C5 chassis). He didn't want it fixed, he just thought I might want it for parts. I remember thinking to myself (as I watched the water dripping out of the cabinet) that it was likely beyond salvaging.

I sat it back underneath the workbench, and forgot about it. After about 7 or 8 months, I thought I'd plug it up and see what would happen. Lo and behold, the thing worked! I cleaned up the outside of the cabinet, took it home, and watched it daily for several years.

Modern stuff is really water resistant, other than paper labels and such.

If it's warm where you are you could set them in the Sun for the day to speed things up without getting them too hot.

Edit: Duh, Florida, might be warm there. :yes:

One of the first sets I restored was a 15" Magnavox from the early 60s. When I got it it was filthy-nasty-disgusting. Having nothing to loose, I put a garden hose on the hot water faucet from the washing machine and let her rip. Added a little suds too, IIRC. After a couple days in the hot California sun I put it back together and it worked perfectly. I used it through college, and a year or two more.

That's a pretty wild story, Dave! I hung my boards to dry near the roof inside my storage shed, which gets like a sauna during the day; very hot and dry. I reassembled the small RCA today; works just as it did before, which is good, but apparently cleaning the board didn't solve the problem! Go figure. :P

I reassembled the 32" RCA late Wednesday afternoon and am happy to report that after replacing the right side speaker (dead; open VC) the set now works perfect! This set was left for dead and sat on the street in pouring rain for 48 hours, so I am proud I was able to save it. There didn't seem to be any issues with it before the rain, aside from that one bad speaker.

Glad to hear you got it working!

I think most modern television sets can withstand a little water or dampness, as long as they have ample time to dry-out before powering it back on again.

I still have the 32" RCA, and it's still working great. I am given a certain personal satisfaction from the fact that I saved it from an untimely death. It went from sitting on a dark, rainy curb to displaying Luigi's Mansion in a warm, dry game room. :)

One time I saved an older TV that had been outside in heavy rain. I just let it dry out for two days and then tried to start it. Vertical was collapsed. I found a joint on a transistor in the vertical section that was almost totally devoid of solder; I patched that up and all was well. I then sold the set.

i have taken a many of nasty circuit boards to the car wash. water wont hurt anything just let it dry good. i use a heat gun then a fan. steve

In the 60s the actual instructions in the repair manual for Tektronix
scopes said to begin a recalibration by thoroughly rinsing with a hose,
the whole thing, then let dry so long. These were the ones with all
the parts mounted between ceramic terminal strips, the ones where the
connection to the ceramic would come undone if you didn't use
silver bearing solder. If you didn't have the special solder, the manual
itself said to pigtail. I made lots and lots of good use of one,
the first model ever to reach 80 MHz. A TV repair person
was astounded when I showed him the waveform at the
output of the IF of a TV, a bright red 9" GE portable mentioned here
recently, undemodulated! It never needed repair, not even
a new tube!