send me your pictures
front and back, and try to clean the board up as best you can, use a heat gun on low heat and carefully remove the wax, so we can see the color codes on the resistors and maybe some other components,
keep the heat away from the ic chip, that little rectangular thing with all the spider legs coming out of it, and also there is a round can that i would try to keep the heat off of too.
you might try mineral spirits and an old tooth brush, it may soften the wax and remove it without heating.
heating can be done safely, if you are careful and use some finesse, that usually comes with experience, so if you are not comfortable doing that, try the mineral spirits, if you are from across the pond i think they call it "white spirits" or somesuch, it is available at the paint stores.
while you have a couple of electrolytic capacitors that have either died or dieing, i don't think they are causing the problem you are having.
in the last picture i think i see one of the slip rings over the top of the board in your hand, in the background, it looks to be in need of a good polishing up. use some fine grit wet/dry paper (around 400grit) and make the rings bright and shiny again.
i can't tell you how many generators quit or become intermittent due to oxidized slip rings and crud on the brushes, i always start with cleaning both up, and i think maybe 90% of the time the generator comes back to life again.
Bruce would know, but i don't think a good design would use electrolytic caps in the voltage reference section of a regulator, used for filtering or smoothing yes, but in a reference circuit? i don't think so, they generally are so loose on their spec's its hard for me to see a use where they would have any application on controlling reference voltages in a regulator.
so i think the regulator might still be working, it is just probably not working as cleanly as it should. and there are components on the board that need clean power, or filtered power, which the electrolytic caps would be used for in my opinion.
in any case, start with the simple, clean the slip rings and the commutator if it has one, and the brushes, the brush faces can be cleaned by placing a strip of 400 grit backside to the slip ring and grit facing up toward the brush, and then simply pull the paper out again, the brush spring will put enough pressure on the brush to hold it against the paper, and the paper being laid over the slipring will maintain the contact arc/shape so that the brush will fit nicely on the now clean slip ring.
if that is over explaining? sorry, i don't know your experience level.
whatever is causing he issue, it probably will be easily rectified (fixed).
bob g
i will pm you my email addy, you might also pm Bruce and sent him the pictures too, he has a lot of experience with regulators on these types of applications, i would defer to his knowledge and use me as a fall back position.
