Tek 2213 attenuator switches

[Piglit]

Have this old 2213 kicking around which had been sidelined because of
dodgy attenuator switches (some positions work fine, some never work
and others sometimes work). Finally got around to pulling it apart and
found the switches charmingly simple - a barrel with pegs (like an old
music box) bearing down on little gold plated leaves contacting gold
plated lands on the PCB. Cleaned everything up with IPA then Cramolin,
and (full of optimism) put it all back together again. To my surprise
it was not a great deal better than before the operation. Anyone know
of any tricks that may get me better results ?
Cheers
M

 

[ehsjr]

Have this old 2213 kicking around which had been sidelined because of
dodgy attenuator switches (some positions work fine, some never work
and others sometimes work). Finally got around to pulling it apart and
found the switches charmingly simple - a barrel with pegs (like an old
music box) bearing down on little gold plated leaves contacting gold
plated lands on the PCB. Cleaned everything up with IPA then Cramolin,
and (full of optimism) put it all back together again. To my surprise
it was not a great deal better than before the operation. Anyone know
of any tricks that may get me better results ?
Cheers
M

This might help:
1) Turn attenuator to open the contact(s) you are cleaning
2) Slide an IPA wetted piece of white paper in the opening
3) Turn attenuator to close the contact(s)
4) Slide the paper out.

*** *GENTLY* ***

Ed

 

[Nico Coesel]

Have this old 2213 kicking around which had been sidelined because of
dodgy attenuator switches (some positions work fine, some never work
and others sometimes work). Finally got around to pulling it apart and
found the switches charmingly simple - a barrel with pegs (like an old
music box) bearing down on little gold plated leaves contacting gold
plated lands on the PCB. Cleaned everything up with IPA then Cramolin,
and (full of optimism) put it all back together again. To my surprise
it was not a great deal better than before the operation. Anyone know
of any tricks that may get me better results ?

The gold plating usually dissapears after the years. What's left is
bare copper which is not suitable as a material for contact. Using
contact cleaning agents only makes things worse because these dissolve
copper and other metals. The only real solution is to replace the
attenuator or fix it properly by having the contacts plated with gold
again.

 

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The gold plating usually dissapears after the years. What's left is
bare copper which is not suitable as a material for contact. Using
contact cleaning agents only makes things worse because these dissolve
copper and other metals. The only real solution is to replace the
attenuator or fix it properly by having the contacts plated with gold
again.

Try a small amount of conductive grease.