I have a friend who has a really old VP where the electronics are mounted horizontally under the temp/humidity section. His solar cell's weather coating has become clouded or hazed quite a bit. From what I gather, Davis doesn't offer replacement parts for this old a model. Does anyone know of a source for a replacement solar cell for this old a VP? TIA!
I would treat it like a sun-clouded vehicle headlight, those plastic ones that came into favor some time ago and periodically degrade.
There are refinishing kits sold (pricey) to renew those headlights to clarity, or do as I do and just use an auto wax/polish, after first cleaning with diluted SimpleGreen (or whatever Davis recommends, think I've seen comments around here about some recommended special alcohol cleaner or something).
Treat it much more gently than with a headlight of course, you don't want to tear the film, or force any liquid/compound under it at the edges. It just takes a little rubbing the compound around on the 'lense', let it dry, and gently buff out with a clean cloth or paper towel.
If the little PV panel was 'OK' or slightly degraded, it should work better. If it wasn't working at all, for other reasons, nothing lost.
If the PV panel needs replacing, almost any size and voltage/current spec panel can be found online at Newegg, Amazon, etc.