Dvd/Cd Laser Diode Current Measurement - Panasonic SA-XH20PH Service Manual

10.2. DVD/CD Laser Diode current measurement

This section will illustrate proceddures of measuring & deriving DVD/CD Laser Diode Current.
Item Description
CD Laser Diode Current Measurement
DVD Laser Diode Current Measurement
Checking Item/Formula
1. Measurement the voltage (V
This is voltage across R8566 which has a resistance value of 4.7 ohm.
2. Calculate the CD Laser current by the following formula:
CD_LD=VCD/4.7
3. Specification for CD laser current is
1. Measurement the voltage (V
This is voltage across R8556 which has a resistance value of 4.7 ohm.
2. Calculate the DVD Laser current by the following formula:
DVD_LD=VCD/4.7
3. Specification for DVD laser current is
40
) on the testpoints CL8530(+) & CL8531(-).
CD
58 mA
) on the testpoints CL8530(+) & CL8532(-).
DVD
58 mA
Remarks
Refer to 10.2.1.
Backend P.C.B.
(Fig. 3. Backend
P.C.B.)
Refer to 10.2.1.
Backend P.C.B.
(Fig. 3. Backend
P.C.B.)