Clean and Lubricate Pots in Tek 475


 

The vertical position pots and the beam intensity pot on my Tek 475 oscilloscope are stiff and scratchy. The service manual says that they are pre-lubricated and sealed, and that no regular lubrication or cleaning is necessary, but I think that this may not still be true 50 years after the unit was manufactured.

I can see that the pots have four screws on the opposite end from the control shaft, but I'm not sure what I would have to do to clean and lubricate the pots once I had them open. Also, the pots in question (part #s 311-1397-00 and 311-1533-00 seem to actually be two pots connected to together, in the case of the first pot, which is used for the vertical input position adjustment, they are two 5K Ohm pots, and the second pot, which is the bean intensity adjustment is one 5K Ohm and one 2.5MegOhm pot).

I've already searched for replacement parts, and have found some promising leads, but I would rather clean and lube the pots in-place than have to unsolder anything (which would require significantly disassembling the scope in order to get at the backside of the circuit boards).

Does anybody have experience re-lubricating these pots, and could tell me what I'm up against?

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