Panasonic SA-AK640PL Service Manual

Contents

Panasonic SA-AK640PL Service Manual Manual pdf 44 page image

13.1. Cassette Deck Section· Measurement Condition−−−− Reverse-mode selector switch:−−−− Deck Tape Select: NORMAL−−−− Make sure head, capstan and press roller are clean.−−−− Judgeable room temperature 20 ± 5 °C (68 ± 9°F)· Measuring instrument−−−− EVM (DC Electronic voltmeter)−−−− Digital frequency counter· Test Tape−−−− Tape speed gain adjustment (3 kHz, -10 dB);QZZCWAT13.1.1. Tape Speed Adjustment (Deck 1/2)1. Insert the test tape (QZZCWAT) to DECK 2 and playback(FWD side) the middle portion of it.2. Adjust Motor VR (DECK 2) for the output value shownbelow.Adjustment target: 2910 ~ 3090 Hz (NORMAL speed)3. After alignment, assure that the output frequency of theDECK 1 FWD are within ±60 Hz of the value of the outputfrequency of DECK 2 FWD.Fig. 113.1.2. Bias Voltage Check1. Set the unit “AUX” position.2. Insert the Normal blank tape (QZZCRA) into DECK 2 andthe unit to “REC” mode (use “l REC/STOP” key).3. Measure and make sure that the output is within thestandard value.Bias voltage for Deck 2 14±4mV (Normal)Fig. 2Fig. 313 Adjustment Procedures13.1.3. Bias Frequency Adjustment (Deck 1/2)1. Set the unit to “AUX” position.2. Insert the Normal blank tape (QZZCRA) into DECK 2 and set the unit to “REC” mode (l use “REC/STOP” key).3. Adjust L1002 so that the output frequency is within the standard value as below.Standard Value: 89 ~ 110 kHzFig. 413.1.3.1. Cassette Deck SectionBelow is the locations of test points for Deck P.C.B.:-44SA-AK640PL