JVC HRJ291MS
Instrukcja Serwisowa

2. Servo Circuit
A. Unstable Video in PB Mode.

Does the on screen noise level change periodically?
YES

Do CTL pulses appear at IC501 pin 97?
YES NO

Does the CFG divideIC501 waveform appear at pin 87?
YES

Is the height of the CTL Head adjusted correctly?
NO

Do the CTL pulses move when TRK is operated?
YES NO

Adjust the CTL Head.

Does the Video Envelope waveform appear at IC501 Pin 9?
YES NO

Replace IC501.

Replace IC501.

Check Y/C Block.

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