Tek465B Restroration

2024/11/3

Tektronix produced such good analoge osciloscope, I trust 400 series scope, they did failed, but almost all of them caused by unfunctional big capctor.

It have been several years i did not seen another 465B. Just after the Tektronix 5111 been fixed, i find this 465B on top of a tall shelf, i obviously like to keep busy on those test equipments i love.

this 465B obviously had failed horizontal defalation system, it stuck on left of the screen could not go to right at all. A detail check reveal vertical system can hardly be said to be working too, vertcal scan trace also messed up, did not look like a sine wave at all.

I did test the working bias from the horizontal deflation all the way back to the scan generator. every stages, no work point is correct. This reminde me one thing, the power supply. I should've check the power supply first. but i always overlook it and go directly to the point look like have problem.

All the restroration of this scope then became to how tear off the big capacitor. The 5V and 15V's cap is dry. the final result is i just sold a new 1000uF(at least 1k uf to make it work) on 15V rail and another 1000uf into 5V rail afer a labor intensive working on removing that cap.

Very sadly, I find this again, the 5V capctitors metal case is part of ground trace, this is a bad design, take me half hour to realize what happens to the 5V rectifier.

And never fogot this: each big cap have 3 claws soldeing in the hole, the easier way could be destroy the old metal can directly(but i had to tell you, destroy that metal can is not easy neither.) I trying to make a special weller solding iron tip to cover 4 solder joints at same time.

But i hope you have desolder gun for working on such stuff, i really miss my disassembly tools.