1.17 ANALYSIS OF BLOCK NOISE (SYMPTOMS: POOR VIDEO, ABSCNCE OF AUDIO) 1.17.1 Analysis Flow Chart In case of trouble, perform troubleshooting using the following flow chart. Start
OK
Play cleaning tape.
Dirt deposited on the head.
NG
Play the recorded tape to measure error rate. Is the error rate less than 500 (one channel) and less than 1000(total) when the viterbi is on?
OK Played tape defect.
NG Check RF envelope. �Is waveform flat? �Are SUP and TU pulses continuous? OK The dirt deposited on the drum. � Clean the drum. 2.12.5 Compatibility Adjustment.
NG
Play cleaning tape.
Play the recorded tape to measure error rate. Is the error rate less than 500 (one channel) and less than 1000 (total) when the viterbi is on?
