I pick up this scope on a trade this last weekend at the SARS meet outside of Atlanta and it worked with a pair of sine waves, very responsive for about 5 minutes then there were a pair of dots that responded vertically but not horizontally. I would like to salvage this scope and learn how to use it. How should I proceed to diagnose and repair this device? Any and all help would be appreciated

Respectfully,
Charles

Hi Charles

The Horizontal sweep circuit isn't operating. The circuit will use an oscillator and amplifier. This signal is fed into CRT deflection plates.

Your scope will have a switch to select different horrizontal frequencies. It may have one position which turns off this oscillator. Rotate the switch and see what happens.

Norm

: I pick up this scope on a trade this last weekend at the SARS meet outside of Atlanta and it worked with a pair of sine waves, very responsive for about 5 minutes then there were a pair of dots that responded vertically but not horizontally. I would like to salvage this scope and learn how to use it. How should I proceed to diagnose and repair this device? Any and all help would be appreciated

: Respectfully,
: Charles

I tried the knob you suggested and all of the others
with no luck. I did notice a smell coming from the scope and discovered an electrolytic cap that is hot to the touch. Should my assumption be that this cap has failed and replace it?

Charles

: Hi Charles

: The Horizontal sweep circuit isn't operating. The circuit will use an oscillator and amplifier. This signal is fed into CRT deflection plates.

: Your scope will have a switch to select different horrizontal frequencies. It may have one position which turns off this oscillator. Rotate the switch and see what happens.

: Norm

: : I pick up this scope on a trade this last weekend at the SARS meet outside of Atlanta and it worked with a pair of sine waves, very responsive for about 5 minutes then there were a pair of dots that responded vertically but not horizontally. I would like to salvage this scope and learn how to use it. How should I proceed to diagnose and repair this device? Any and all help would be appreciated

: : Respectfully,
: : Charles

Hi Charles

Yes, replace any cap the gets warm. That's a common failure mode of electrolytic caps. They get leaky, heat, short and can destroy other components in your scope. Replacing it may cause your scope to start operating again?

Norm

: I tried the knob you suggested and all of the others
: with no luck. I did notice a smell coming from the scope and discovered an electrolytic cap that is hot to the touch. Should my assumption be that this cap has failed and replace it?

: Charles

: : Hi Charles

: : The Horizontal sweep circuit isn't operating. The circuit will use an oscillator and amplifier. This signal is fed into CRT deflection plates.

: : Your scope will have a switch to select different horrizontal frequencies. It may have one position which turns off this oscillator. Rotate the switch and see what happens.

: : Norm

: : : I pick up this scope on a trade this last weekend at the SARS meet outside of Atlanta and it worked with a pair of sine waves, very responsive for about 5 minutes then there were a pair of dots that responded vertically but not horizontally. I would like to salvage this scope and learn how to use it. How should I proceed to diagnose and repair this device? Any and all help would be appreciated

: : : Respectfully,
: : : Charles