tek 2235 scope p/s problem

[pindiode]

hi
i have a mil version tek 2235 scope
it is missing q908 on board
i think it is a scr.anyone have a scan
of the service manual p/s page?

thanks doug/aar3ir

 

[Jim Yanik]

t.com:

hi
i have a mil version tek 2235 scope
it is missing q908 on board
i think it is a scr.anyone have a scan
of the service manual p/s page?

thanks doug/aar3ir

If it is the SCR,it's in an overvoltage crowbar circuit,with a 51 V
zener,shorts a 3 ohm resistor to ground to put the PWM IC into 'burst'
mode. Tek p/n 151-0506-00,mfg.# C106B2X283(mfg=General Electric).
It's all part of a pre-regulator that knocks rectified line V down to ~43
Vdc for the power oscillator.

Sorry,I don't have any 2235 schematics.
The PS is similar to my 2213 PS.
The 51 V zener can also be out of spec and causing the SCR to trigger
prematurely.

 

[Mike]

The service manual lists Q908 as a PNP TO-92 transistor, mfg p/n 2N2907A, TI
p/n 151-0164-00.

 

[Jim Candela]

Doug,

I just checked Bama (bama.sbc.edu) an FTP web site. They have a 2225
Manual for download. Maybe that will help.

Good luck with that scope!

Regards,
Jim

 

[pindiode]

hello everyone
thanks for the help
i read some of the old posts
on this scope and should be able
to get it going now,thanks again

doug/aar3ir

 

[TekMan]

Doug,

I just checked Bama (bama.sbc.edu) an FTP web site. They have a 2225
Manual for download. Maybe that will help.

Good luck with that scope!

Regards,
Jim

...snip..


The circuit of the 2225 Scope is completely different to the 2235/2215
scopes.

And, as far as I can check this on bama, the 2225 manual is operating
only, not the service manual (so there are no schmeatics).

hth,
Andreas

 

[Jim Yanik]

[email protected] (TekMan) wrote in

..snip..


The circuit of the 2225 Scope is completely different to the 2235/2215
scopes.

And, as far as I can check this on bama, the 2225 manual is operating
only, not the service manual (so there are no schmeatics).

hth,
Andreas

Yes,a 2213 or 2215 (or 'A' version) manual would be more applicable to
working on a 2235 PS.

An 'A' version manual would be most similar.