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Advance OS250 oscilloscope X-shift issue

Hi,
I just picked up this "golden oldie".
The only thing not working well is the horizontal or X-shift. The trace cannot be shifted to the right enough to fill the right most 25% of the screen.
So my guess is that the Timebase / X amplifier circuit has an issue.
 Only thing so far I checked are the 170V and the +- 20V rails, which are ok.

Any ideas anyone, please?

Comments
lcsaszar
lcsaszar picture

Check the X amplifier final stage transistors that drive the deflection plates.

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Jan-Willem
Jan-Willem picture

Hi Icsaszar; I did and indeed one of the BF258´s is dead. 
I´ll replace it and hopefully issue should be gone.

Many thanks for your fast and great advise!

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SzBálint
SzBálint picture
***

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