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No video signal, color and audio ok
While testing this morning the video signal disappeared (with a delay time of one or two seconds). No sync, picture with full contrast control has few contrast, and looks inverse, like a film negative. Sound ok, color seems ok too. With no tuner input signal, a contrast rich noise (snow) is on the screen like before in such cases. I assume a defect video detector (1N60).
Testing the first video amplifier tube 6aw8: first grid and positive end of video detector 2.7v instead of 19v, kathode 8.2v instead of 22v, anode 217v instead of 148v, 2nd grid 188v instead of 170v.
Kathodes of the crt appr. 310volts. Do you know this failure?
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