Tektronix 465B repair

[scatterandfocus]

It sounds like I'm better off leaving well enough along on the caps.  But I will check the power supply ripple, just to see what it looks like.  And by the way, when I checked voltages after swapping the shorted C4331, all were within 0.2V except for the 110V, which was 111.5V, if I remember correctly.  I did notice that in the replacement parts list of the service manual, C4331 is listed as an electrolytic 47uF 20V (pdf pg. 209, service manual 7-17).   

Good to know on the horizontal position pot.  Thanks.  I thought that maybe some little part was missing in there.

And yea, the trace does sharpen up a bit with the 20Mhz limit switched on.

[scatterandfocus]

I turned on the 465B today and got no display again.  Oh no.  Something else has failed.  Making my way through the Tektronix Troubleshooting Your Oscilloscope pdf, I ended up in the section, Troubleshooting Faults in the Timebase, where part of the check setup is to set Trig Mode to Single Sweep.  After switching Trig Mode back to Normal, my trace reappeared.  What I had been doing previously before powering off was playing around with the Add function.  I had left both probes connected to the calibrator port with Add and Invert engaged and Trig Mode set to Normal.  Any way, everything seems ok again, but I'm left wondering why I got a blank display in the first place.

Ok, back to looking at the 6227B power supply.

[Alfons]

In normal-mode, you only see the signal when it is triggered. In auto-mode you can see the traces without being triggered.

[bd139]

Yep.

In NORM mode, stick the trigger coupling on DC and sweep the trigger level up and down to get a triggered sweep.