Morning (UK time)
At Tek in the UK, at the old Harpenden site in the late 70's, we used to jet-wash 'scopes (the older 500 series, and some 400 series.? With an industrial detergent/water mix, then rinse with the same washer filled with plain clean water.
The tool was more like a large bore paint sprayer, compressed air would draw the fluid from the cup, and expel it as high speed liquid and foam, or just aerated water.? A choice of sash brushes were used on the front panel to remove suborn dirt.
You'd be amazed at the amount of dirt and other crud that would come out!? Some of the kit was believed to be used underground, from the name of the customer.
Then, they were left in a drying oven heated to something like 40'C with passive ventilation for a week at least.
The 500 series usually needed the fan motor bearings (and some rotary switches) re-lubing, plus the filter mesh replacing if it fell to pieces during it's prior removal and wash (no bad thing.) The 400's just left to dry, and maybe a few switches dosed with a small amount of IPA or similar solvent, NOT "Switch Cleaner".? I don't recall any issue with damaging any pot's or transformers, and certainly to my knowledge, no CRT's were damaged.
Most of the older 'scopes would then power up (if not actually "Faulty") and many even worked to specification after warmup.
In those days, we'd do a full performance check* and re-calibration "Adjustment" to get best performance anyway, none of this modern faff just check if it's "in spec'", rubber stamp a document stick another sticker over the old ones and out the door with it, that happens these days.
(* Recording the results before and after cal', if the customer wanted, for extra ? or $.)
Electronics is remarkably tolerant to water, so long as it is not powered up at the time, and any dirt/residue that accumulates in low spots doesn't affect anything HV or RF related.? But, it has to be thoroughly dried out of course before power is re-applied later..
Regards to All.
Dave B.? Ex Tektronix UK.? (Harpenden, later Maidenhead.)
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