Sanyo HV-DX4EV Service Manual page 8

TROUBLESHOOTING
B. Playback picture doesn t appear
PB video signal missing.
YES
NO
Is Envelope output from IC301
Is 5V supplied at IC301 pin#91?
pin#79?
Is SW Pulse input at IC301
YES
Is Y SIGNAL output at IC301
Is 5V obtained at IC301 pin#24,
NO
pin#46?
Check and Replace IC301.
YES
Does X301(4.43MHz)
NO
Is Y SIGNAL input at IC301
NO
Check PATTERN
pin#43?
YES
Is VIDEO SIGNAL output at IC301
NO
Check and replace IC301.
pin#65?
YES
Same as EE MODE check.
NO
Check POWER 5V.
YES
NO
Check IC501 pin#18.
pin#70?
YES
Clean head or Replace head.
NO
Check POWER 5V.
42,55,72,91?
YES
YES
Check PATTERN
oscillate?
NO
Replace X301.
12
C. No recording
Record video signal poor.
Check EE MODE.
YES
Is luminance and color signal NO
Is signal input into IC301
output from IC301 pin#78?
pin# 48,50,52,54,56?
YES
NO
Check POWER circuit.
Is +5V supplied at IC301 pin#91?
YES
NO
Is IC301 pin#80 REC(H) HIGH? Check IC501 pin#45.
YES
Is VIDEO SW Pulse input at IC301
NO
Check IC501 pin#18.
pin#70?
YES
Is REC signal output from IC301
NO
Replace IC301.
pin#94,95,89,90?
LP MODE: 89,90 Pin
SP MODE: 94,95Pin
Check video HEAD and Connector.
13
TROUBLESHOOTING