Thanks for the response
It does make sense as you say not to use the method if not needed and only on a suspect deck.
It was a great method in my opinion on the Panasonic deck. I tend to treat most decks from car boots as suspect, as many will have been stored in unknown/damp conditions, you can often tell by the musty smell, which seems to be around 50% of the decks I obtain from boot sales. Otherwise perfectly functional or with minor problems such as capacitors needing replacement and a transport clean.
There was very little I could find about UV light damaging electronics with the exposure times I use, bar the accidental erasure of EPROMS (the window most often covered with a label), or damage to rubber (hence my covering of those components such as idlers and the pinch roller before turning on the lamp).
Doing more digging since my post for a few hours came up with this one thing: There was a mention that Aluminium Electrolytic Capacitors should not be stored in an area where UV exposure is a problem:
http://www.elna.co.jp/en/capacitor/a...on/detail.html, how this would affect other capacitors is unknown, but they must have a reason to state this as they are a manufacturer of capacitors. And I am unsure if that means long term storage, or what a brief exposure to UV light will do, and the wavelength.
Weather this would harm for a 1 - 2 hour exposure time I do not know and could find very little data on UV light exposure to capacitors, though I did not notice any problems with use of the decks for a while after the UV exposure, the Panasonic is still good for my use and it is used daily. I am guessing mileage may vary depending the light source being UVA/B/C, I used a UVC lamp.
The only other thing is maybe it could somehow alter the grease used for lubricating the transport components, but I am unsure of that one without knowing the specific lubricant.