Prima PS-42T8 Service Manual page 30

4.2 YPrPb or YCrCb no picture
Check if the YPRYPB input pin
of N700 have signal.
4.3 TV no picture
Check if AV channel
is normal.
Normal
N700 damaged
Check if YPRPB1 / YCRCB1 and YPRPB2
/YCRCB2 channels is no picture.
Yes
Yes
Check N700 and
periphery circuit
Check if the input signal of
N700 is normal.
Normal
Abnormal
Check if N700 has
No
output.
No
check interface
No
circuit.
Abnormal
Check
Yes
periphery circuit
28
Check N903
M52797 and the
tuner.
N602 and