Toshiba CN27E90 Technical Training Manual page 134

(B) OSD IS OK, PICTURE DOES NOT APPEAR (A/V CIRCUIT IS DEFECTIVE)
Check waveform at pin 36 (Y-AV)
or QV01. 2V
P-P
NG
Check waveform at pin 30 (Y-Comb) or QV01.
NG
Check waveform at pin 38 (V-AV) or QV01.
NG
Check input waveform. 1V
Video1 Pin 12 of QV01
Video2 Pin 10 of QV01
Video3 Pin 16 of QV01
NG
Go to (D), (E)
OK
Check Q501. Go to (B).
OK
Check QV01.
OK
Check Comb filter. Go to (B).
P-P
OK
Check QV01.
134