Sharp IM-MT899H Service Manual page 41

• Abnormal display
Is waveform output from CN451 pins 3 to 5 ?
Are the pin 2 (VCC) and pin 12 (GND) normal ?
Yes
Check for pattern breakage of flexible PWB, check for
defects of display microcomputer (replace the display unit).
• Audio playback clrcult
In the normal playback mode, LCD play time display functions, but no audio is heard.
Is audio waveform output from IC501 pins 15 and 16 ?
Yes
Is audio waveform output from IC703 pins 8 and 17 ?
Yes
Is audio waveform output from J703 pins 3 and 4 ?
Yes
Check headphones jack, and periphery of headphone.
• The spindle motor does not rotate.
Does the waveform appear on the IC201 pins 24 and 25 after
TEST mode AUTO2 completion and in this state ?
Does waveform appear on the IC601 pins 28 and 33 ?
Does waveform appear on IC601 pins 57, 59 and 61 ?
Check the soldering of CN601 and the flexible PWB, or
replace the spindle motor.
Yes
Yes
Yes
Is waveform output from pins 2, 54 and 58 of IC401 ?
No
Yes
Check between IC401 and
CN451.
Check pins 70 to 72 and 74 of IC201, and pins 9 to 12 of
IC501.
No
Check pins 4 and 21 of IC703 and pins 15 and 16 of IC501.
No
Check for defective solder joint of audio signal line between
IC703 and J703.
No
Check the periphery of IC201.
No
Check the periphery of IC601.
No
If the waveform is not observed after resoldering of C601,
No replace it.
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IM-MT899H/IM-MT899W
No
Check the periphery of IC401.