Sammy said:
Many instruction booklets for domestic electronic equipment say do
not use cleaning solvents such as alcohol.
Is this advice given simply because they are trying to prevent
possible marking of the plastic casing?
Or can domestic cleaning solvents actually damage the electronics
inside in some way?
Alcohol is one of the more innocuous of the organic solvents. I doubt
that it would attack any plastic case, but other solvents can. One thing
that alcohol can do is dissolve the labelling ink on some circuit boards
or components. This would make repair (i.e., replacement based on the
component value or board number) difficult, maybe dangerous if it
happened that a lower-voltage component were substituted, for example,
because the original component's label had become smudged or obliterated.
Solvents might dissolve the lubricant on switch contacts, or sliders, or
disperse it over potentiometer tracks causing later problems. Spraying
solvent into equipment may damage speaker cones or piezo speakers.
Liberally dripping solvent into equipment may cause it to malfunction,
e.g., an air-gap capacitor trimmer will have different parameters when
the dielectric is liquid solvent, and if the solvent is flammable it
might cause a fire from static electricity or a switching spark. If a
cleaning solution were to leave an hygroscopic residue on a circuit board
this could initiate electrochemical corrosion (copper/brass + lead/steel/
aluminium in contact in a conductive solution). Water-based cleaners with
ammonia will be conductive, so could short out tracks on a board.
.
