Philips DVDR630VR Service Manual page 27

VCR ELECTRICAL TROUBLESHOOTING GUIDE
3. Y/C CIRCUIT
(2) When the Y(Luminance) signal doesn't appear on the screen in PB Mode,
Is 5.0V 5.3VA applied to IC301
Pins24, 42, 55, 72, 91?
YES
Is I 2 C BUS signal applied to
the IC301 Pins68, 69?
YES
Does the normal RF signal
appear at IC301 Pin 78?
YES
Does the Y(Luminance)
RF signal appear at
IC301 Pin79?
YES
Is the Y(Luminance) Video
waveform showed up at
IC301 Pin43?
YES
Replace IC301.
NO
Check the line of the 5.0V
5.3V Line. (Power Circuit)
Refer to 'SYSTEM I
NO
BUS CHECK Trouble
Shooting'.
NO
Is the V.H.S/W signal
applied to IC301 Pin70?
Is the V.H.S/W "H" about
3.4V at the IC301 Pin70?
Clean the Drum.
Check the path of the
NO
Y(Luminace) RF signal.
(Check the C312)
Check the path of the
NO
Y(Luminace) RF signal.
(Check the C327)
3-13
2 C
NO
YES
NO
YES
NO
Check the System Circuit.
(IC501 Pin23)
Check the V.H.S/W level.
(Check R303, R304)
Replace the IC301.