wrote:

Would it be a good idea, for example, to remove the flyback ? The
horizontal scan transformer ! The tuners ?

I think before undertaking this all this must be considered, but
ultrasonic would greatly accelerate the process.


I do a lot of coolant leaks (3 Mitsus this week), and IMO the only
reliable way is to totally clean the board with ammonia and soap. I
use a product called Parsons Sudsy Ammonia dilluted about 5 to 1. The
ammonia suggestion comes from RCA. I tried several experiments by
putting coolant on scrapped PCs, and trying different cleaners and
solvents by contact only, no wiping or blotting. The ammonia is the
only thing I tried that really disolves the coolant and leaves the
board totally dry.

I remove any and every component that can hold\trap water, such as
transformers, tightly wound inductors, flyback, tuner, and all dense
edge connectors from the board. I then spray the complete assy with
the ammonia mixture several times over a half hour or so, until the
entire board is bright and shiny. I then rinse the board thoroughly
with scalding hot water several times ( I don't use deionized or RO
water, just tap). If any of the connectors had coolant contamination,
I clean these in the same way and dry quickly so they won't rust. I
replace any obviously burned or damaged components, reassemble the
board and try it. If it's not working, repair as usual. Single sided
boards usually work first shot. Multi layer boards like Mitsus often
have feed through failures. Under a high power loop, they usually
look blackened or swollen. Sometimes the only way of finding an open
feedthrough on a multi layer board is with an ohmmeter.

Removing all these components from the board before cleaning is time
consuming, but IMO it's the fastest way in the end.

John