Tektronix 2230 psu rebuild question.

[pitpat]

Hi, recently I've got on my bench this really nice (yet big) scope.
It probably has some problems on the
pre-regulator section since the crowbar system got in action giving the tik-tik sound.
Surfing a bit on the internet i found out that a viable solution might be to feed 43v on a testing point skipping all the pre regulation.
Since from what I've read this technique it's meant more for a test rather than a solution, do you guys think it might be good for a
permanent fix? Should I look for a particular switching psu?

Also English is not my native language so be kind on me

Thanks a lot for checking in!
Federico

[pitpat]

Service manual in here: https://de.tek.com/manual/2230-service-manual

Schematics should be at page 372

[bob91343]

It's a common problem.  I solved mine by replacing the IRF power transistor on the power supply board.  Nicer fix than to have a separate power supply.  But that works also.  Not critical.

[David Hess]

Surfing a bit on the internet i found out that a viable solution might be to feed 43v on a testing point skipping all the pre regulation.
Since from what I've read this technique it's meant more for a test rather than a solution, do you guys think it might be good for a
permanent fix?

I know of at least one person who did that successfully.  As I recall, they found a small 48 volt off-line switching power supply which could be adjusted down to 43 volts to drive the inverter.

[pitpat]

Ok, thanks a lot! i think that i'll try to fix it before get into the plan b.
Also i'm trying to check the capacitors ESR with a cheap LCR. What values should be considered to be replaced in this situation? I'd say below 1 ohm should be "fine" or at least not trigger the crowbar.
Am i right?