Sony DNW-A220 Maintenance Manual page 111

For Channel Condition NG
Confirm, recheck, and clean the drum (video heads) according to the procedures below.
(1) If no abnormality is found during PB CH CONDITION check but abnormality is found during REC
CH CONDITION check, perform as follows.
. Readjust the recording current.
. Record a data again for two minutes or more.
. Perform the REC CH CONDITION check.
If no abnormality is found, recheck and readjustment are completed.
n
The data is overwritten on a cassette tape in REC CH CONDITION check.
Before check, record a data on a blank tape for two minute or more.
(2) After that, perform the REC CH CONDITION check after recording a data again for two minutes or
more. Perform the cleaning using a cleaning tape
(in Section 4-2-1).
If no abnormality is found, the recheck is completed.
(3) After that, perform the REC CH CONDITION check after recording a data again for two minutes or
more. Perform the cleaning using a cleaning tape again (the amount of the tape used is 15 seconds).
If no abnormality is found, the recheck is completed.
(4) After that, perform the REC CH CONDITION check after recording a data again for two minutes or
more. Perform the cleaning with cleaning cloth
(in Sections 4-2-2 ).
If no abnormality is found, the recheck is completed.
If the error condition is not improved in the way mentioned above, the possible cause below are consid-
ered.
. VTR's servo system adjustment defect or circuit defect
8 Readjust the servo system. (A0 : SERVO ADJUST)
8 Check the servo system. (C03 : REEL/CAPSTAN MOTOR & FG CHECK)
. Worn PB head in the drum assembly
8 After confirming the hours meter (H02 : DRUM RUNNING HOURS), replace the upper drum
assembly as required.
(Refer to the maintenance manual part 2, volume-1.)
. Adjustment defect in tape transport system or component part installation defect.
8 Readjust the tape transport system or reinstall the parts
(Refer to the maintenance manual part 2, volume-1.)
. EQ-72 board defect
. Drum assembly defect
DNW-A220
DNW-A220P
3-2. TAPE Maintenance Mode (M0)
3-2-3. RF CHECK Mode (C1)
3-35