I have a Tek 2235 o scope with a 1 1/2¡± vertical solid and fixed y-axis amplitude display that appears on both channels. Changing gain has no effect on the display, neither does changing the focus. Sweep timing is good. CRT display is bright. Using a 500 mV 1kHz square wave at the input does not have any effect on the screen display problem. Referencing the Tek service manual, I cannot find anything on the board amiss using another external oscilloscope to checkwaveforms. What is interesting is that the output signals leading to the upper and lower vertical control plates of the CRT appear clean and undistorted showing the 1kHz square wave, so the the problem must be in the CRT, or the associated circuitry. Has anyone seen this problem or know someone who does? I don¡¯t know how to upload a photo quite yet, but I will figure it out soon.
