Tek 464 with busted "delay sweep " friction switch

vaclav_sal
 

After almost a year of procrastinating I am trying to fix this "friction switch" / worn out problem.
For whatever reason I can move the delay sweep switch , I painted the friction surface and it does the job, sort off, but I cannot pull the knob.
If I remember right there is a spring to "pop " the switch back to normal.

Anyway - two question to the group
1. Is the "time base board" unique to the 464 or is it common to other 4xx scope?
There are nonworking scopes on e-bay I may be able to swap the timing switch to make the 464 work again.
There is NOTHING else busted on my 464 , just the friction switch given up the ghost..
2. Does anybody has broken 464 with WORKING delay sweep friction switch to sell?
Or just the board with WORKING delay sweep friction switch?

I would appreciate NOT to discuss "what is the delay sweep friction switch " - if you have no knowledge about it you cannot help me.
Hope you understand my remark.

Cheers

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