Sharp VL-AX1S/H Service Manual page 26

VL-AX1S/H/E/EW/EX
ADJUSTING THE ELECTROMAGNETIC CONVERSION CIRCUIT SYSTEM
1. PLL VCO adjustment
Mode VCR ADJ mode
Procedure 1) Playback the alignment tape (or a self-recorded tape).
2) Call the adjustment mode (V-ADJ).
3) Set the address "2A" and call the data.
4) Set the called data with the FF/REW key to the point where the playback screen appears.
(At this time, the screen full of block noise is OK.)
Examples • During E
2. Phase and equalizer adjustment → (Performed in the VCR mode)
Mode VCR ADJ mode
Procedure 1) Load a self-recorded tape into the deck.
2) After playback for 3 minutes, select the test mode 0F using the remote control for adjustment to start the
automatic adjustment. (The following sequence is automatically performed.)
The built-in VI/O
colour bar is recorded.
3) A power source is put again after a power source is cut once.
4) Error rate check
Select and fix the TEST MODE 0B on the adjustment remote control.
5) Manual adjustment method (video adjustment mode)
* Perform this adjustment with the self-recording/playback in the LP mode.
For phase, vary the data for the address 26 and 2B, and for equalizer, vary the data for the address 25 and 27,
to set the error rate is made as small as possible.
H ch side
L ch side
Examples • During mechanism replacement. • During circuit board (Main) replacement. • During E
2 PROM replacement. • During circuit board (Main) replacement.
PB
VS REW
Synchronization error
Phase Equalizer
H
2B 27
L
26 25
Phase and
equalizer are
Judgment
adjusted
automatically.
Error rate
Synchronization error 20 or less
Error rate
26
OK:
Tape is EJECT.
Blue LCD comes on.
NG:
Red LCD comes on.
200 or less (SP Mode)
330 or less (LP Mode)
2 PROM replacement.