ELECTRICAL ADJUSTMENT-5/6
2. Servo Adjustment (RF PLL Adjustment)
* * This adjustment can be performed even when the TOP cabinet, operation board or TFT block is removed. To avoid counting track jumps as errors, track jumps are not performed in the test mode and recorded spiral pits are read, unlike during normal DVD playback. Therefore, during service mode startup, only the Aiwa logo appears; the pictures and sound recorded on the disc are not output. During test mode startup, the OPEN/CLOSE detection switch is disabled. During test mode startup, keys other than the POWER key are disabled. The test mode automatically ends after 6 minutes (The disc rotation stops.) To continue the test mode, turn on the power again.
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No. 1 2 3 4 5 6 7 8 9 10
Contents Short pin-4 and pin-6 (ground) of CN400 (not mounted). (Preparation for test mode startup) Connect CH1 of the oscilloscope to TP400 (IC400 pin-5) and connect CH2 to TP315 (IC450 pin-60). Insert the test disc (MDVD-191). Turn on the power. (The test mode starts) Confirm that the pickup reads the outermost circumference of the disc. Rotate VR300 right while checking the waveform of TP315 becomes 4.5±1.0V. Check that the waveform of TP315 is fixed HIGH and the voltage of TP400 is less than 400mV. Turn off the power and turn on again. Confirm that the pickup moves to the innermost circumference. Check that the waveform of TP315 is fixed HIGH and the voltage of TP400 is less than 400mV.
