Teac DV-H500 Service Manual page 12

4. FRONT Circuit (Digtron & Key)
STRAT
Power ON.
LED ON?
YES
Is Display on normally?
YES Check the pattern between
IC91 and FIP1.
Do all the
buttons work
normally?
YES
of IC91 Pin 51 - 54 .
Check and replace D901,
D902, D907, R932, R933,
R934 and R935.
Does remote
control work
normally?
YES
Complete repairing Front B/D.
END
NO
Is oscillation of
X901 normal?
YES
NO
Check waveform
of IC91 Pin 32 .
YES
NO
Is waveform of IC91
Pin 42 normal?
YES
Check waveform
NO
YES
Solder defective parts again.
Does pulse
NO
waveform of Rs51 Pin 1
appear?
YES
Is IC91
Pin 62 Connected to
Rs91 Pin 1 ?
YES
Replace IC91.
YES
NO
Check Power.
NO
Replace Q902.
Check waveform
NO
of IC91 Pin 51 - 54 .
YES
Replace IC91.
Check waveform
of Q901 and Q902.
YES
Replace D906.
NO
Is Rs91 Pin 3 5V?
YES
Replace Rs91.
NO
YES
Re-solder.
YES
2-12
NO
Solder Key part.
NO
Replace Q901 and Q903.
NO
Solder defective part.
Recheck