We’ve all ‘been there’ - and I’d welcome any advice and counsel with regard to your own individual approaches and experiences!
Yesterday’s ‘patient’ was part of a Sony Mini Hi Fi system that I’m in the process of restoring - this module being the TC H500 twin ‘auto-reversing’ cassette tape deck unit. I’ve worked on many tape decks before [including another one of this particular model] - and I wasn’t looking forward to it .... given that transport access etc. necessitates major autopsy/dismantling. This unit is now some thirty/forty years old and was impregnated with nicotine and infested with dust of indeterminate composition! It was obvious that the drive belts had long since given up the will to live, but that the pinch rollers remained perfectly serviceable. So, apart from deep-cleaning [even the boards were ‘sepia toned’!] a few ‘repairs’ were necessary i.e. load-latch mechanisms, drive belt replacement, and a re-lube etc. etc.
And here’s the rub! The drive belts [an unfair description of these particular specimens!] were the worst artefacts that I’ve ever encountered! Remnants were scattered around the transport - but most had fused to the capstan flywheels, idler, and motor pulley - and thereafter assumed the properties of un-set polysulphide/silicone sealant!
I donned a pair of nitrile gloves [several in fact] and set to work armed with: a toothpick, cotton buds, scraper and a catering flagon of IPA [and some meths too]. This ‘revolting mess’ will adhere to anything that it touches, and is difficult to remove from your hands too i.e. without appropriate solvents etc. (Each ‘nasty shovel-full’ was therefore progressively smeared onto a piece of kitchen tissue and repeatedly disposed of as the mission progressed ...)
Given that this unit utilises vee rather than flat belts - I grudgingly removed the metal capstans/flywheels [+ spacers/thrust washers] and spent a long time raking-out the belt grooves and lands, mindful that any residue could pick-up on the replacement belts and impair playback and recording quality [which is usually very good on these decks]. The idler and motor pulleys are however of nylon composition and rather more difficult to disassemble - so these were done in-situ (and perhaps because of their material composition), were marginally easier to clean.
As mentioned earlier, I have always used IPA as a cleaning solvent for this ‘horrid’ job - mindful that other more aggressive solvents [e.g. lighter fluids etc.] may damage adjacent plastic-based components.
The unit has now been reassembled, and performs perfectly - but this was never a job that I wanted to throw myself at - and sincerely hope that I don’t encounter a similar challenge for some [considerable] time!
So - my question is this: what has been your own approach, method[s], tools and materials when confronted with this awful crud?
