Sharp MD-E9000H Service Manual page 72

MD-E9000H
MD SECTION
Preparations
If dusts and foreign materials are accumulated on the pickup lens, playback sounds can be skipped or the TOC (Table of Contents)
can't be displayed. Clean the object lens and check the playback. When lens are dirty, do the following.
Turn off the power and wipe lens softly with a cleaning paper and a little cleaning solution so as not to damage it.
Do not touch lens with bare hands.
If the MD unit doesn't work
If the MD unit doesn't start after cleaning the pickup objects lens, check it as follows.
Is disc loading normal ?
Is playback state set when the MD PLAY/PAUSE button is
pressed ?
Is audio output normal ?
Is record and playback operations normal ?
• Playback state cannot be set.
Is it impossible to set both high reflection disc and low
reflection disc to playback state ?
Only the high reflection disc can be played back.
Is 2.7 V to 2.8 V applied to the pin 93 of IC1401 with the high
reflection disc inserted ?
After re adjustment check as stated in item "Normal playback".
• Audio playback circuit
When sound is not output although the playback time display advances during playback in the normal mode.
Is audio output waveform observed on the pins 24 and 26 of
IC1701 ?
Is audio output waveform observed on the pins 15 and 17 of
CN1501 ?
Check the main PWB.
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Check as stated in item "disc Loading is not normal".
No
Check as stated in item "Playback state cannot be set".
No
Check as stated in item "Audio playback circuit".
No
Check as stated in item "Record and playback operations".
No
Check as stated in item "TEST mode check".
Yes
No
Only the low reflection disc can be played back.
Yes
Is 2.5 V to 2.6 V (record enabled) or 2.7 V to 2.8 V (record disabled)
applied to the pin 93 of IC1401 with the low reflection disc inserted ?
No
No
Yes
Check loading motor PWB, and CW1931 and SW1932.
Check the pins 70, 71, 72 and 74 of IC1201, and the pins 12, 16,
No
17, and 19 of IC1701.
Check connection between IC1701 and CN1501.
No
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