� Method-2 (In service mode or normal operation): Check the value of current flowing in the laser diode. 1. Remove the upper cabinet. 2. Read the current printed on the label attached on the rear side of the optical pick-up.
(Label stuck outside of the optical pick-up)
KSS-331C
24Y59
day
action number year month
� MAIN Board � (Side B)
SA350
Q501
Indicates current value. (In this case, 35.0 mA) A current value will vary depending on the set.
IC601
IC501 IC502
3. Connect a digital voltmeter as shown in Fig. 2. 4. Press the � key. 5. Calculate current value by the reading of the digital voltmeter. Reading of the digital voltmeter (V) ÷ 4.7 (�) = current value (A) (Example) Reading of the digital voltmeter of 0.1645 V: 0.1645 V ÷ 4.7 � = 0.035 (A) = 35 mA 6. Check that the current value is within the following range. � Current value of the label +5 mA (25�C) �11 Variation by temperature: 0.4 mA/�C Current increases with temperature increased. Current decreases with temperature decreased. If the current is more than the range above, there is a trouble in the automatic power control circuit or the laser diode is in deterioration. If less than the range, a trouble exists in the automatic power control circuit or the optical pick-up.
