Zenith XBR413 - Page 13

3-6
VCR ELECTRICAL TROUBLESHOOTING GUIDE
No 28V (HSR)
Check or Replace
the D129
Is the Vcc(30V) supplied
to Q120 Collector?
Is the Vcc(33V) supplied
to Q121 Collector?
Is the Vcc(30V) sup-
plied to Q120 Base?
NO
NO
Check or Replace
the ZD153
NO
Check the ‘HSR “H”
signal from µ-com
Check or Replace the
Q121/Q122 & 33V line
YES
YES
Check or Replace
the Q120
YES