Tek 464 with busted "delay sweep " friction switch


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.




thanks .The ( very good ) reference link talks about the "pull the knob" to engage the delayed sweep friction "clutch" and the spring which pulls  / holds it back in "normal " position. 

I have a feeling I accidentally  glued the spring so it cannot move.

it looks as it is a common part to other typesof 4xx scope - the whole switch - and I should be able to replace just the "delayed sweep " part, which includes the clutch ,  to really fix it.

Of course if somebody has "spare " 464 timing board I would prefer  just to replace the whole board.


On Saturday, August 31, 2019, 9:16:14 AM CDT, gerry182@... <gerry182@...> wrote:

This may be of help



Just a note

Found the "delay sweep" spring stuck inside the switch barrel.
It looks as the part where the spring rests is busted so the spring gets jammed in when pushed.
The only solution is to replace the "delay sweep" barrel to make the friction work again.