Sony D98 chassis Operation Manual page 26

Range
1V-4V
Cutoff
Red
Control
Cutoff Circuit
Green
D/A from
Blue
IC001
R107
C105
Similar to
Red
Channel
To IC003 A/D Converter
- Heater voltage at the cathode.
-+12V, +5V, and G2 voltage coming from D board.
2) Color Restoration doesn't work. Bad color after restoration, check:
- Check waveforms at pins 6, 11 and 14 of IC004.
- Trace these signals through the rectifier back to IC003.
- If there are no waveforms at pins 6,11, and 14 then IC004 may be suspect.
4. Display Data Channel Circuits (DDC)
This display can support two video sources. The front input supports DDC2B. While the rear input supports DDC2Bi. For
DDC2B (Front Cable) IC007 is a serial memory device providing Extended Display Identification or EDID data that is read
by the compatible Host Computer on Pin 5. The basic EDID format consist of 128 bytes which are described in the table
below. The 15 Pin VGA connector allocation is also described. The compatible Host Computer provides a V CLK on Pin 7
that is derived from the V Sync input and is used to set the timing of each data reading cycle. The data is clocked by the
input of IC007 Pin 6. The rear input supports DDC2Bi. The data is passed through the A Board to the Microprocessor on the
N Board via CN311.
Troubleshooting Hints
1. The DDCB circuit should be checked if error DDC messages or erroneous monitor identification data is indicated by
DDC2B the compliant Host Computer. Check that the V CLK and S CLK signals are input to IC007 on Pins 7 and 6. The
Data transition should be visible at Pin 5.
Beam Current Sensing Circuit
D104
C106
C206
C306
D105
Video
Driver
D106
D206
R119
D306
R120
R105
IC004
4 2 5
7
6
10
9
V-
- 11
12
V+
+
2 13
13
6
D108
R108
R116
C121
R115
C108
D120
R122
Beam Current Sensing Circuit
From IC001 D/A Converter
G2 Control Circuit
+B +B
R316
R219
R320
R220
Range 1V-4V
R048
- -
26
CRT
Range 400V-800V
R064 R048
R053
D045
13
IC005
Q1
2
5
V+ R045
12
11
3
V-
6
C048
R31
R049
R047