Here is a few screenshots of current state. On the trigger board I found a diode that was cracked. It is D517. I looked up the Tektronix part number but could only find it was a signal diode.
![](https://www.eevblog.com/forum/other-blog-specific/170-tektronix-465-review-and-troubleshoot-part-1/?action=dlattach;attach=462352;image)
![](https://www.eevblog.com/forum/other-blog-specific/170-tektronix-465-review-and-troubleshoot-part-1/?action=dlattach;attach=462358;image)
I just removed it and tacked in a 4148 for testing.
As you can now see I have trace on channel 1 with the trigger mode set to auto.
![](https://www.eevblog.com/forum/other-blog-specific/170-tektronix-465-review-and-troubleshoot-part-1/?action=dlattach;attach=462364;image)
Channel 2 as well.
![](https://www.eevblog.com/forum/other-blog-specific/170-tektronix-465-review-and-troubleshoot-part-1/?action=dlattach;attach=462370;image)
I now have the probe attached and this is the resulting wave form. Either sweep or trigger issue.
![](https://www.eevblog.com/forum/other-blog-specific/170-tektronix-465-review-and-troubleshoot-part-1/?action=dlattach;attach=462376;image)
I can grab the time base or any other control on the right side of the scope.
![](https://www.eevblog.com/forum/other-blog-specific/170-tektronix-465-review-and-troubleshoot-part-1/?action=dlattach;attach=462382;image)
As soon as I turn or push I loose trace.
![](https://www.eevblog.com/forum/other-blog-specific/170-tektronix-465-review-and-troubleshoot-part-1/?action=dlattach;attach=462388;image)
Really does not matter what control I play with on the right hand side I will loose trace. Perhaps it is time to remove boards and give the controls a good cleaning.
Also wanted to add that turning the unit off then back on restores the trace. Trigger knobs also have no effect.