ELECTRICAL TROUBLESHOOTING GUIDE -6/10
-69-
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NO
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START
Do all the
buttons work
normally?
Check waveform of
IC901 Pin 14.
Check waveform
of IC901 Pin 18, 19.
Is Digitron on normally?
LED ON?
Check waveform
of IC901 Pin 7.
Is oscillation of
X901 normal?
Is waveform of IC901
Pin 21 normal?
Check waveform
of IC901 Pin 14.
Does pulse
waveform of RC901 Pin 1
appear?
Is IC901
Pin 17 connected to
RC901 Pin 1 ?
Is RC901 Pin 2 5V?
Power on.
Check and replace
R903,R912, R904, R905,
R941, R906, R907.
Solder defective parts again.
Solder defective parts
Replace IC901.
Solder Key part.
Check Power.
Replace IC902.
Replace IC901.
Replace LED913.
Replace RC901.
Re-solder.
Recheck
Replace IC901.
Complete repairing Front B/D.
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NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
CD
4. Front Circuit (Digitron & key)
www. xiaoyu163. com
QQ 376315150
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TEL 13942296513
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Q
TEL 13942296513 QQ 376315150 892498299
TEL 13942296513 QQ 376315150 892498299