Tektronix 2230 Issues

[hadmeister]

Hello, I ve bought an old Tektronix 2230 and it has some issues. The biggest one is that I can not focus the traces (or the readout text), the intensity knobs don´t work at all and so the scope is stuck on full brightness. In addition the blanking is not working quite right. I checked the PS for ripple or voltage issues and it turned out to be just fine (besides the 2kV rail, I don´t have a meter to do it) I think there must be problem somewhere in the Z axis driver, but in the service manual the waveforms are almost unreadeable. The only thing I can tell for sure is that the waveform going out from the Z axis amplifier looks the same as the waveform in the manual, as far as I can tell from the poor quiality picture. There is unfortunately no waveform or voltage that I could check after the DC restorer.  The other problem is that it shows up a powerup failure on startup, unfortunatelly, due to the blurry image, I can not read it to get more info. on that, could be just the battery because other than that the scope appears to be working jsut fine. Can you help me please?

[singapol]

Reading this will help:

www.sphere.bc.ca/test/tek-parts/troubleshooting-scopes.pdf

Check the intensity and focus circuit but be careful of high voltages!

Edit: Read the adjustments of power supply and crt on pg. 5-4 t0 5-5.

[hadmeister]

After some poking around. It unfortunately looks like a bad CRT  The bias of the control grid changes between app. 40 to 70 V as I turn the intensity pots but the intensity itself does not change at all.     I will try to look more closely at the caps and diodes in the DC restorer but my hope for feasible repair is slowly disappearing. If the fault won´t be there I will have to live somehow with that.