Daewoo SD-8100, Service Manual

Page: 13 / 63

13
TROUBLESHOOTING
B. Playback picture doesn’t appear
YES
YES
Is Y signal output at IC301
pin#46?
Is Y signal input at IC301
pin#43?
Is Video signal output at IC302
pin#3?
Check and Replace IC301.
Check PCB Pattern.
Playback picture doesn’t
appear.
Is Envelope output at IC301
pin#79?
NO
NO
YES
Is Video signal input at IC601
pin#50?
Is 5V obtained at IC301
pin#91?
Is SW Pulse input at IC301
pin#70?
Is 5V obtained at IC301
pin#24,42,55,64?
Check POWER 5V.
Check IC601 pin#18.
Check and Replace HEAD.
Check POWER 5V.
YES
NO
NO
Does X301(4.43MHz) oscillate?
Check Pattern.
NO
NO
NO
YES
NO
NO
YES
YES
YES
YES
Replace X301.
Is Video signal output at IC301
pin#65?
Check IC301 pin# 62.68,69,70.
NO
YES
Check PCB pattern
NO
IC302 pin#9,10,11(control
DC), 16(Vcc)
NO
Check
Pattern.
Check IC604 PIN#3(C sync)
YES