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Sony Kv27exr25 chassis scc-d50f-a

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marco antonio

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scc-d50f-a

This tv has no audio and no picture. All voltages from the power supply are correct. I measured Hv and read 22kv. Voltages at the katodos are good, 200v.
The filament is on but nothing more. Any idea.
rgds
marco antonio
 

marco antonio

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sony kv-27exr25

In short the filaments are on, HV 25kv approxx, audio ok, power supply voltages normal. I moved the screen pot an the raster is visible. I took volatges at IC301 and some values are abnormal like these:
16 5.30 (3.9) 17 5.3 (3. 18 5.35 (3.9) 19 4.29 (5.5)
20 0.26 (2.3) 21 4.8 (6.0) 22 0.26 (1.9) 23 4.33 (6.2)
24 0.26 (1.9) 26 7.0 (4.7) 27 0.20 (7.7) 38 1.8 (2.7)
44 1.90 (2.4) 45 1.7 (2.2)

Readings in parenthesis are from schematic. Is the IK protection the reason these readings change if so what action could I do/
rgds
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marco antonio

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sony kv27exr25

For audio replaced IC, ok, for picture found the scren pot intermitent and resistor of 1M with value changed,280k, replaced them and ckd ok.
rgds
marco antonio
 

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