SONY TC-D505 (01) PDF Document

The torque specifications are as follows:

1. Clean the following parts with a denatured-alcohol-moistened swab:

• record/playback head
• erase head
• capstan
• pinch roller
• rubber belts
• idler

2. Demagnetize the record/playback head with a head demagnetizer.

3. Do not use a magnetized screwdriver for the adjustments.

4. After the adjustments, apply suitable locking compound to the parts adjusted.

5. The adjustments should be performed in the rated power supply voltage unless otherwise noted.

The Test mode is activated by shorting Test Point Service mode (IC851 pin 34 changes over to “L”) with the POWER switch in OFF position, then turning on the POWER switch.

In this mode, the following functions operate:

1. Source monitor. Line mute is cancelled during recording.

2. High speed playback. High speed playback is executed when the HIGH SPEED (DUBBING) button is pressed during playback. Normal speed playback is restored when the button is pressed again.

3. Record memory. The tape counter is reset to “0” at the record start point.

After adjustment, open the Service mode to cancel the Test mode.

Switches and controls should be set as follows unless otherwise specified:

DOLBY NR switch: OFF

DIR MODE switch:

Standard Record: Deliver the standard input signal level to the input jack and set the REC LEVEL control to obtain the standard output signal level.

Standard Input Level:

Standard Output Level:

The following test tapes are used:

Procedure:

1. Mode: FWD playback. Use test tape P-4-A100 (10kHz, −10dB).

2. Turn the adjustment screw for the maximum output levels. If these levels do not match, turn the adjustment screw until both of output levels match together within 1dB.

3. Perform Phase Check. Mode: playback. Use test tape P-4-A100 (10kHz, −10dB).

4. Set in the REV mode and repeat step 1-3.

5. After the adjustment, lock the screws with locking compound.

Procedure: Mode: playback. Use test tape WS-48B (3kHz, 0dB). Perform high speed adjustment before normal speed adjustment.

(High speed adjustment)

1. Continue pressing the SYNCHRO DUBBING HIGH SPEED switch.

2. Check that frequency counter reading is within the standard value 6,000±30 Hz.

3. If out of the standard, adjust each RV72 so that the frequency counter reading satisfies 6,000±30Hz on both A and B decks.

4. Change over to REV playback status, and repeat the above steps 1 to 3.

(Normal speed adjustment)

1. Continue pressing the SYNCHTO DUBBING NORM SPEED switch.

2. Check that the frequency counter reading is within the standard value 3,000±30Hz.

3. If out of the standard, adjust each RV71 so that the frequency counter reading satisfies 3,000±30Hz on both A and B decks.

4. Change over to REV playback status, and repeat the above steps 1 to 3.

Frequency difference between the beginning and the end of the tape should be within 3%.

Frequency difference between deck A and deck B the beginning of the tape should be within 1.5%.

Procedure: Mode: playback. Use test tape P-4-L300 (315kHz, 0dB).

Adjust RV11 (L-CH), RV21 (R-CH) so that the reading on VTVM meets the adjustment limits below.

Adjustment Limits:

LINE OUT level: −5±0.5dB (0.42–0.46V)

Level difference between channels: less than 0.5dB

Check that the LINE OUT level does not change in playback mode while changing the mode from playback to stop several times.

Setting: REC LEVEL control: Standard Record.

Procedure:

1. Mode: record. Input signal source: 315Hz, 24.5mV (−30dB) and 10kHz, 24.5mV (−30dB).

2. Mode: playback recorded portion.

Playback the signal recorded in step 1. Confirm that the 10kHz playback output is 0±0.5dB relative to the 315Hz output. If necessary, adjust RV12 (L-CH), RV22 (R-CH) and repeat the steps given above.

Setting: REC LEVEL control: Standard Record.

Procedure:

1. Mode: record. Use unrecorded tape CS-122. Input signal: 315Hz, 24.5mV (−30dB).

2. Mode: playback recorded portion.

3. Playback the signal recorded in step 1. Confirm that the signal level is within the adjustment limits below. If necessary, adjust RV101 (L-CH), RV 201 (R-CH) and repeat the step 1–2.

Adjustment Limits: −25dB±0.5dB (42–46mV)

Check the antenna terminals, metal trim, “metallized” knobs, screws, and all other exposed metal parts for AC leakage. The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed metal part having a return to chassis, must not exceed 0.5 mA (500 microampers).

Leakage current can be measured by any one of three methods:

1. A commercial leakage tester, such as the Simpson 229 or RCA WT-540A. Follow the manufacturers’ instructions to use these instruments.

2. A battery-operated AC milliammeter. The Data Precision 245 digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated AC voltmeter. The “limit” indication is 0.75 V, so analog meters must have an accurate low-voltage scale. The Simpson 250 and Sanwa SH-63Trd are examples of a passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2V AC range are suitable.