Laser Power Adjustment - Sony MDX-C800REC Service Manual Supplement

For the measurement points, see page 7.

LASER POWER ADJUSTMENT

Connection:
optical pick-up
objective lens
MD servo board
TP (I+3V)
TP (IOP)
Procedure:
<Setting the write power reference value>
1. Connect a digital voltmeter between TP (I+3V) and TP (IOP).
2. Set the test mode. (See page 2.)
3. Insert a laser power meter into the disc insertion port and press 5
key.
4. Press 2 key.
LCD display
Mode No. 7.0 mW power
(LD Power Adj.)
5. Use DISC + or DISC – key to adjust so that the reading on
the laser power meter is 6.9 to 7.1 mW.
6. Press + > M key for 2 seconds to save the data that has
been set in step 5.
7. Verify that the digital voltmeter reads out the specified value.
Specified value:
Reading on the digital voltmeter: Optical pick-up label indication
value ±10%
(Optical pick-up label)
KMS-263A
2 7 X 9 3
B 0 8 2 5
In this case, Iop = 82.5 mA
Iop (mA) = Reading on the digital voltmeter (mV)/1 (Ω)
4
laser power
meter
digital voltmeter
+
–
<Setting the read power reference value>
8. Press 2 key.
LCD display
Mode No. 0.7 mW power
(LD Power Adj.)
9. Use DISC + or DISC – key to adjust so that the reading on
the laser power meter is 0.69 to 0.71 mW.
10. Press + > M key for 2 seconds to save the data that has
been set in step 9.
11. Press 2 key.
LCD display
Mode No. Main beam conversion power
(LD Power Adj.)
12. Verify that the reading on the laser power meter is 6.0 to 6.4
mW.
If outside the specified value, adjust again from step 1.
13. Press 2 key. The laser power adjustment is completed.