Toshiba CN27E90 Technical Training Manual page 136

(E) PICTURE ONLY VHF/UHF OF SUB SCREEN DOES NOT APPEAR(B) OSD IS
OK, PICTURE DOES NOT APPEAR
Picture of only VHF/UHF of main screen
does not appear
Check waveform at pin 15
of HY01.
NG
Check power voltage of HY01.
Pin9 9V
Pin7 5V
Pin2 32V
OK
Replace HY01.
OK
Check waveform
at pin 28 of QV01.
NG
Check power circuit.
136
OK
Replace QV01.
NG
Check CV09,
RV12.