Telefile Adjustment - Sony GY-8240UWD Maintenance Manual

5-16. Telefile Adjustment

5-16. Telefile Adjustment
When replacing the CCM-33 board or SE-606 board, be sure to perform the following adjustment.
Measuring instrument:
. Adjusting plus screwdriver (Ceramics)
. Oscilloscope
. Personal computer
. Terminal emulator software
. Connecting cable (RS-232C crossed cable)
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Refer to Section 5-14-1 for the measuring instruments used.
Preparations
1. Turn the power off.
2. Remove the front panel. (Refer to Section 1-1.)
Adjustment Procedure
Pay careful attention to the following points to perform the adjustment correctly.
. Do not perform adjustments on the SE-606 board of other GY-8240 machines.
. The SE-606 board must be attached to the unit.
. Do not place cassette, memory labels, and other metal objects (excluding the chassis plate) near the SE-
606 board.
1. Set the oscilloscope as follows.
VERTICAL
CH1: 5V/DIV, DC
CH2: 5V/DIV, DC
MODE: CH2 INVERT, ADD, 20 MHz BW LIMIT = OFF
HORIZONTAL
20 ns/DIV
TRIGGER
CH1, DC
LEVEL: 5V
2. Connect the oscilloscope as follows.
CH-1: TP1/CCM-33 board
GND: Chassis plate
CH-B: TP2/CCM-33 board
GND: Chassis plate
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Do not connect the GND of the probe to the CCM-33 board. Otherwise the
CCM-33 board may damage.
3. Connect the connector (OPTION1) of the IF-780 board and personal computer
using the connecting cable.
5-180
CN1
TP1
TP2
CT1
CCM-33 Board (A Side)
GY-8240UWD
GY-8240FC