Part-1
LASER DIODE CHECKING METHOD & SERVICE MODE ENTRY METHOD
LASER DIODE CHECKING
Method -1
- Open the upper lid.
- Push the [S423]
- Press [CD >|| ] key.
- Check the object lens for confirming normal emission of the laser diode. If not emitting, there is a trouble in the automatic power control circuit or the Optical pickup. During normal operation, the laser diode is turned On about 2.4 seconds for focus and searching.
Method -2
- Remove the upper panel.
- Connect a digital voltmeter between TP(10P1) and TP(10P2); can located at the right top corner of the PCB. {Main board: Conductor side}
- Press the { CD >|| } key.
- Calculate current value by reading of the digital voltmeter. [The reading of the digital voltmeter (V) / 2,2Ohms + Current value {A}. Example: Reading of digital voltmeter of 0.082V: (0.082/2.2Ohms = 0.037A = 35 mA). Current value of the specified: 16 to 18 mA.
- If the current is more than the range above, there is a trouble in the automatic power control circuit or the Laser Diode in the deterioration. If less than the range, a trouble exists in the automatic power control circuit or the Optical Pickup.
SERVICE MODE
Step-1
- Connect TP447(CD TEST-2) to TP444(GND). {LCD board: Component Side}.
- Turn On the S423 (CD open Switch).
- Insert external power supply.
- Connect TP453 (Reset) to the TP444 (GND) to make open. (Reset)
Step -2
- Once the service mode is effected, the LCD displays [18] indications each of which is repeatedly displayed.
- By pressing [ >>| ] or [ |<< ] key, the optical pickup is movable inwardly or outwardly. However, it this is activated, tracking servo and sled servo are turned Off. So it can be turned ON by pressing the 'BAND" key if required.
- Without disc, focus search is repeated continuously.
- By pressing "Band" key, tracking servo, sled servo and CLV-A (servo in Play) are turned ON. Then playing begins. No muting is On in the service mode.
RESETTING OF SERVICE MODE
- Remove the external power supply.
- Disconnect TP447 & TP444, and also TP453 & TP444.
Test Mode Continued: on Part -2