On Monday, February 12, 2018 at 5:40:36 AM UTC-5, wrote:
"Back when projection TVs were plagued with coolant leaks, I used to soak the entire circuit board in an ammonia and soap solution. But *first*, everything that can trap water must be removed. Back then, that meant SMPS transformer, HOT and flyback XFRs, inductors,etc. A lot of work but it fixed stubborn symptoms and no call backs. "

I had a different technique. I washed it in hot water, then alcohol, then acetone with a brush and then blew dried it on hot to evaporate everything.. And then sprayed with spray solvent to make it cold. That squeezes the **** out of the board, which is quite porous. Repeated about 4 times. The last time left the acetone or alcohol on it, heated it up with the blow dryer and waited a while until you could not smell it anymore.

Seems like a lot more work than a one step soak. We received a bulletin from RCA about coolant leaks, and they suggested ammonia based detergents as the most effective way of removing the coolant and it's associated contamination. I had a PTK195 that would do all sorts of very intermittent weird things in the vertical circuit even after a regular cleaning. I found a product called Parson's Sudsy Ammonia and used that diluted in a parts washer. The board were spotless and even glossy after drying.



I remember old AA and AB GE chassis bubbling under the solder on the gripletts which impeded their soldering. And those were about 90 % of the problems with those sets.

My brother (the hero) used to hard wire those GEs through the griplets but I used to just solder the bottom, solder the top, then resolder the bottom again and give it a good spay of Flux-Off (the original stuff). That took less time than it might seem and they never came back.