iwatsu ss-6122 oscilloscope

[yashiro32]

iwatsu ss-6122

Hi,

I bought a Iwatsu ss-6122 oscilloscope for a year and recently when i turned it on,
i could not find the trace. I tried to adjust the vertical position knob to the highest position and i could see the trace appearing at the bottom of the screen. After that, when i adjust the vertical position knob to lower down the position the trace seems to adjust down and cannot be seen anymore. Does anyone know which parts or components of the circuit the problem lies on?

 

[yashiro32]

ss-6122

one of the push pull transistor in the vertical deflection output amp Q34 - 2SC1412 (NPN tranistor) is damaged . As that part is obsolete, i replced it with a cross reference part - 2N5109 and the trace returned to the center of the screen .

But now, there is another problem. After i turned on the oscilloscope for around 15 -20 minutes there seems to be a double image drifting vertically up and down corresponding the trace and readings . Where could the problem be ? Could it have something to do with the Focus/Z-axis part of the circuit ?

 

[yashiro32]

iwatsm:ss-6122

Does anyone have the service and user manual and the schematic diagram of this IWATSU ss-6122 oscilloscope?