Hi all,

I got hold of this cheap ($100) Tek 485 that is working fine except for
three things: The variable volts/div pot on channel B doesn't pop up
smoothly, and when it does it doesn't turn at all; the lights on the
100M/50R selection on channel B don't work (the switch works though),
and the variable timing pot doesn't turn.

Never having done anything on a 485 I opened up the case, turned it
upside down, and I can see the two aluminum "boxes" for the channel
attenuators. I removed the knobs from the B channel and a few screws,
and I can "pop" the attenuator back, but not enough for me to actually
pull it up and get to it -- it meets the power supply board too soon
(there's also a little aluminum "T" connecting the A and B boxes).

Is there any way for me to get to the attenuator circuitry without more
serious dismantling? I downloaded a copy of the service manual but it
didn't help much.

Best,

- Cesar