Just ordered some wd 40 electronic cleaner. 6.50 a can, may try to rinse with some hot water in a squirt bottle.
its a pioneer spec 4 amp and the boards come out pretty easy. I will see if the wd 40 loosens the grime. May try some
hot water and dawn detergent. looks like this thing was in a nicotine environment.
Everything gets sticky then the dust fuses to it.
Don't use WD40, it is not intended to be an electronics cleaner, it removes water, lubricates and leaves a residue.
Here is how I did it with a really filthy SX-780.
Remove wood covers and other likely to be damaged-by-water parts.
Take chassis or boards outside, and set on hard surface so liquids can drain away.
Saturate with Simple Green and let it soak for a while.
Rinse it with water, you can brush with a soft brush if needed. Be careful not to flood it, just rinse and drain.
Repeat Simple Green and rinse/brush treatment if needed.
Blow away water with compressed air or similar, gently, don't blast it real hard, it is not necessary.
Rinse down well with isopropol (99%) or denatured alcohol to remove the last of the water.
Blow dry gently again.
If it has a receiver with mechanical tuning capacitor rinse the fins with a non-residue electronic cleaner.
Let it sit in a warm place overnight, to finish drying and alcohol evaporation, A warm incandescent light bulb and/or fan helps.
Deoxit switches and controls with appropriate type.
SX-780 before clean:
SX-780 after clean:
I use a shop-vac and duct tape a small hose to the one of the attachments, like a fish tank hose. Then use windex or simple green with a acid brush and scrub down the board staying away from the pots and coils. Get it nice and wet. Then vacuum it off. I do this a couple of times. Then let dry. I do use different size hoses so some will fit over caps and transistors and smaller ones to get into tight spots. Works great to get the 's party smells out of them.
Deoxit works too, but is expensive.
Deoxit is for controls, not circuit boards.
Don't use WD40, it is not intended to be an electronics cleaner, it removes water, lubricates and leaves a residue.
WD40 sells different formulas now. They have a non residue cleaner. Of course keep the original WD40 away from electronics!
https://www.wd40specialist.com/products/contact-cleaner/
Sorry, I can't track down the pics (or even remember if I kept them), but a few years back I bought a couple Carver PM 1.5 (fan cooled pro amps) that had been used by a band that specialized in "barn dances"--as in being held in actual barns full of hay. Filters got clogged, so they pulled them--didn't replace them--just pulled them. You should have seen what was inside.