Denon RCD-M39, Руководство по обслуживанию

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NOTE HANDLING AND REPLACEMENT OF THE LASER PICK-UP
1. Protection of the LD
Short a part of the LD circuit by soldering. After connection to a circuit, remove the short solder.
2. Precautions when handling the laser CD mechanism
• Handle the laser pick-up so that it is not exposed to dust.
• Do not leave the laser pick-up bare. Be sure to cover it.
• If dust adheres on lens of the pick-up, blow it off with a blower brush.
• Do not shock the laser pick-up.
• Do not watch the light of the laser pick-up.
3. Cautions on assembling and adjustment
• Be sure that to the bench, jig, head of soldering iron (with ceramic) and measuring instruments are well grounded.
• Workers who handle the laser pick-up must be grounded.
• The finished mechanism (prior to anchoring in the set) should be protected against static electricity and dust. The
mechanism must be stored that damaging outside forces are not received.
• When carrying the finished mechanism, hold it by the chassis body
• For proper operation, storage and operating environment should not contain corrosive gases. For example H2S, SO2,
NO2, CI2 etc. In addition storage environment should not have materials that emit corrosive gases especially from
silicic, cyanic, formalin and phenol group. I the mechanism or the set, existence of corrosive gases may cause no
rotation in motor.
4. Determining whether the laser pick-up is defective
Protective soldering place for laser diode.
Measure the waveform at RFO on "MCU CD PCB
w
RFO".
(For measuring points and waveforms, Rrfer to 50 page.)
Laser drive current (Iop) check
(For how to check, see 4. CD test mode, 4.7.Laser current is display.)
Traverse Unit replacing
Disc no read, unsteady playback, etc.
Laser current (IOP) memorizing after replacement
NO
Range between 0.4 and 1.1(Vp-p)
Present value exceeds the initial value
by 1.5 times
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