Tektronix 2230 vertical problem

[John D]

Hello,

I have a Tektronix 2230 that seems to have developed a fault: changing the
vertical position of channel A affects the position of channel B and
vice-versa. They are no longer independent of each other. It's kind of
like the two channels are in add mode, which as far as I know isn't the
case (it's set to ALT, and the switch is functioning). Does anyone know
where I might download a free schematic, or be able to suggest what part
might be at fault?

Thanks for any help!

 

[whit3rd]

Hello,

I have a Tektronix 2230 that seems to have developed a fault: changing the
vertical position of channel A affects the position of channel B and
vice-versa. They are no longer independent of each other. It's kind of
like the two channels are in add mode, which as far as I know isn't the
case (it's set to ALT, and the switch is functioning). Does anyone know
where I might download a free schematic, or be able to suggest what part
might be at fault?

The two channels have one element in common: an amplifier power
supply. It's possible that the vertical amplifier power has
inadequate
filtering (a bad capacitor). Sometimes you can find a bulging or
leaking electrolytic capacitor by simple visual inspection.