For engineers analog oscilloscopes are a bit like vinyls and tube amplifiers: Most don’t use them anymore, but if they see one, they think: Nice! And are happy that they don’t have to deal with them on a daily basis 😉 However, I bought a Tektronix 465B with a faulty second channel, just to repair it. For this one, I made a quick YouTube video.
A word of caution: High voltages found inside of analog oscilloscope can cause damage, severe injury or death. If you are not authorized or qualified to work on such devices, don’t do it. I don’t take any responsibility for actions you take or the results of these actions. You do everything at your own risk.
After the initial tests with the BAT41 diode I ordered a proper replacement: the 1N5711. Also, I replaced some capacitors, including a slightly discolored tantalum capacitor. Then I powered the scope up and… Nothing. Did I blow it up? As it turned out a cable soldered to the line switch got loose. After solving this small issue the scope finally started doing its job again. Almost at least. I went through large parts of the calibration/adjustment procedure to bring channel 2 up to speed and make it a bit more accurate.