Panasonic NV-J42B Service Manual

TechInfo Sheet fax: 01344 853689

Audio Visual email: av.technical@mail.panasonic.co.uk

Product Group: Video Model: NV-J42B Date: 30/09/98 Revision No: 01 Document No: 01 Subject: High Pitch Tone

SYMPTOM: High pitch tone is apparent in power off mode.

CAUSE: The unit causes blocking oscillation due to fluctuating input AC voltage

over 260v.

COUNTERMEASURE: Add a capacitor (0.01uF/50v) between Q1103-3 pin and 4 pin to decrease

feedback loop gain of ratio of transmitting current.

*Add a capacitor 0.01uF/50v (Part No. ECQB1H103 or ECWM1H103JZ)*

PROCEDURE:

1. Resolder pin 3 and 4 of Q1103.

2. Insert 0.01uF/50v to the same positions with pin 3 and pin 4 of Q1103 from the component side of power supply PC board.

3. Solder pin 3 and pin 4 of Q1103 positions.

NOTE: Please refer to Service Manual for NV-J42B, Page 4-2, 4-34.

for NV-J47B, Page 4-2, 4-40.

Panasonic CS U.K. Document No: 01

Model: NV-J42B