Sharp IM-MT899H Service Manual page 42

IM-MT899H/IM-MT899W
• Recording/playback operation
1. Insert a low reflection disc, and ascertain audio output by normal playback, and then set TEST REC mode.
Change MSL from 00H to 80H by the control setting of EEPROM. After completing the operation, return in to 00H.
Does the head move down to lead the unit to the recording
state if you set the unit to the continuous recording mode
after setting the address ?
Does the RF waveform appear at TP201A when recording/
Playback is performed ?
Is the level of pin120 of IC401 different between recording
and playback ?
Is RF pattern output from IC201 pin 50 ?
Check the periphery of IC101 and whether the laser diod is
broken.
Check for defects of IC351, IC353, IC354, D351, the head
and the flexible PWB.
2. The audio signal is usually input from line input while
recording is paused.
Check whether input waveform is observed on the pins 5
and 6 of IC701.
Is audio waveform observed on the pins 10 and 12 of
IC701 ?
Is the output waveform output to the pin 8 of IC501 ?
Check the periphery of IC501 and the waveform of the pins
70 to 73 of IC201.
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Check voltage of pins 84 and 87 of IC401, pins 2, 3, 6, and 7 of
No
IC651, pins 4 and 5 of CN601. Check whether disc is record-
inhibited.
Check periphery of IC401.
No
Check for soldering failure of IC201 .
No
Check whether the audio signal line between IC701 and J701 is
No
defective.
Check whether the voltage of pins 13 to 15 of IC701 varies with
the recording VOLUME +/– button operation. Check whether the
No
soldering of IC701 is poor.
Check whether the pin 13 of IC501 and the pin 45 of IC401 are
No
in H state.
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