I have a 2 band QRP transceiver ( made in China ) the AF gain pot has gone dead except one spot at about half full gain. The circuit board is surface mount. Back in my tube days I would put a few drops of 'volume control lube' in the pot to clean it up. But this pot is VERY small and I don't know if it has a carbon strip and a 'wiper' or some other way to change resistance. I don't want dissolve the carbon with the wrong lube. Any ideas ? There is a hole in the pot case where a lube could get in. It does not appear that a new pot could be put on the surface mount board.