Re: Tek 475 no horizontal


Roger Evans
 

It looks like something has caused XY mode to be activated. If you really wanted XY mode it looks like you should depress only the Ch2 button on the vertical mode selector but having both Ch1 and Ch2 depressed probably produces the mixed movement on Ch1.

If you haven't selected XY on the Time/Div switch then check for 5V on pin 18 of U600, this indicates that something else (faulty cam switch segment?) has caused XY mode to be activated. XY mode activates the lockout function on the sweep controller. The 1MHz square wave you see is probably the Ch1-Ch2 chop frequency.

Regards,

Roger

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