Chapter 7. Flowchart Troubleshooting - Sharp HR-MB3 Service Manual

HR-MB3
CHAPTER 7. E Market HR-MB3 Service Manual HR-MB3 Audio
FLOWCHART
[1] Troubleshooting
Abnormal display
Is 7 V applied to TL700 ?
Is waveform sent to TL735 - TL740 and TL743 - TL750 ?
The LCD panel is defective.
Audio playback circuit
During playback, playback time display advances but sound is
not heard.
Is voltage applied to pins 1, 8, 14, and 27 of IC301 ?
Is waveform sent to pins 3, 4, 5, 6, and 7 of IC301 ?
Is audio waveform sent to TL304 and TL305 ?
Check the headphone jack and headphones.
Yes
Yes
Yes
Yes
Yes
No
Check soldering of IC405, D407, L405, Q406, R422, R423,
R446, and C426. Check peripheral circuits of IC405.
No
Check peripheral circuits of IC201, IC500, SC500, IC700, R709,
and the LCD flex PWB.
Is waveform sent to TL735 - TL740 and TL743 - TL750?
Check peripheral circuits of IC100.Check peripheral
circuits of IC100.
No
Check soldering of IC301, IC302, D303, D304, R301, R304, R305,
and R342.
No
Check peripheral circuits of R308~ER310, R312, R315, R101~
ER102, and R132~ER135.
Is waveform sent to pins 3, 4, 5, 6, and 7 of IC301 ?
Check peripheral circuits of IC100.
No
Check soldering of IC301, R344, R345, C312, C313, R321, R323,
R337, R338, FB300, and FB301.
7 – 1
Recheck
No
Recheck
No