Bypass Mode Y Out Level Adjustment (Bw Board); Ntsc Mode Adjustment; Clamp Pulse Width Adjustment; Burst Gate Pulse 2 Width Adjustment - Sony BKM-142HD Maintenance Manual

2-2. BYPASS Mode Y OUT Level
Adjustment (BW Board)
Note: The following adjustment menus are below the
BKM-127W menu of the MAINTENANCE menu.
Y LEVEL
1. Input the PAL color bar signal into INPUT 2.
(100% White Ref. 75% Saturation)
2. Set 02 CH and turn ON the MONO SW.
3. Connect the oscilloscope to TP261 of the BW board.
4. Adjust the Y LEVEL data so that the signal level
becomes 645 mV.
5. Turn OFF the MONO SW.
TP261 (Y)
645 ±10 mV
Y
Fig. 2-1.
BKM-120D/127W/129X/142HD

2-3. NTSC Mode Adjustment

1. Input the NTSC color bar signal into INPUT 1.
(100% White Ref. 75% Saturation, 7.5% Setup)
2. Select 01 CH.

2-3-1. Clamp Pulse Width Adjustment

Note: The following adjustment menu is below the BKM-
127W menu of the MAINTENANCE menu.
CLP W
1. Input the NTSC color bar signal.
2. Connect the oscilloscope to TP325 of the BW board.
3. Adjust the CLP W LEVEL data so that the pulse width
(A) becomes as shown in Fig. 2-2.
TP325
(CLP W)
a
A
b
Specification A = 1.5 ± 0.25 µsec
Fig. 2-2.

2-3-2. Burst Gate Pulse 2 Width Adjustment

Note: The following adjustment menu is below the BKM-
127W menu of the MAINTENANCE menu.
BGP W
1. Input the NTSC color bar signal.
2. Connect the CH1 probe of the oscilloscope to TP261
of the BW board, and connect the CH2 probe to TP322
of the BW board.
3. Adjust the BGP W data so that the output waveform of
the oscilloscope becomes as shown in Fig. 2-3.
TP261
a
b
TP322
Specification A = 3.4 ± 0.1 µsec
Fig. 2-3.
a=b
A
a=b
2-3