Sony CA-550, Maintenance Manual, Page: 20 / 114

2-2 (E)
CA-550
CA-550P
2-3. Circuit Description
The CA-550/550P mainly consists of the following boards.
MD-103 board
The MD-103 board modulates the luminance signal Y, the
color difference signals R-Y and B-Y. And it selects a
signal to be input/output at GENLOCK IN/PROMPT OUT
connector. And also it quadrature-modulates the Y signal
and SKIN GATE signals with the carrier of 22.5 MHz and
the R-Y and B-Y signals with the carrier of 45 MHz. The
resultant signal is sent to the CCU.
AU-211 board
The CHU/RCP data is input/output from/to the AU-211
board. And processings for the audio signal such as the
INCOM mode switching and gain control are performed.
The received data from the RCP goes through the photo-
coupler and is then send as the RX DATA to control the
camera (CHU), via the 68P I/F connector to the CHU. If
the CCU is connected to the unit, the RX DATA is auto-
matically send to the CCU. As for how to select the
INCOM mode, refer to Section 1-4 “Function of Internal
Switches — AU-211 board”.
TR-90 board
The TR-90 board modulates/demodulates the audio signals
such as the MIC, INCOM and PGM. It also demodulates
the H CONT signal and modulates/demodulates the CHU/
CCU DATA. And it also generates the TONE signal,
piggybacks it on to the CHU DATA and ther modulates
the resultant signal.
DM-98 board
The DM-98 board demodulates the RET VIDEO signal
and also selects an output signal at the RET OUT connec-
tor. The relationships between the switch setting and
output signal are given in Section 1-4 “Function of Internal
Switches — DM-98 board”.
Communication with CCU
The CA-550/550P is not provided with the microcomputer,
so it communicates with the CCU through the camera.
A IIC bus line is equipped for the communication between
the camera and camera adaptor. The IIC bus line is also
used for the interface with the CCU.
2-4. Self-Diagnosis
The CA-550/550P has a diagnosis mode used for self-
diagnosis of every plug-in board. The diagnosis page is
displayed on the viewfinder screen of the camera.
• Equipment required
Color Video Camera BVP-550/550P
CCD Unit OHB-450/550 series
Supply power from a camera control unit CCU-700/
700P, AC adaptor AC-550/550CE or VTR.
• Switches and Button
2-3. Circuit Description
2-4. Self-Diagnosis
• Operation
1. Set POWER switch to CCU/EXT position. (If the
VTR is connected, set to VTR position.)
2. Set DISP switch to MENU position. Operation menu
will be displayed.
3. Rotate MENU SEL switch to display “Diagnosis”
page and then press MENU SEL switch.
4. The menu page is returned to the previous page every
time CANCEL button is pressed.
5. To exit Setup menu, set DISP switch to OFF.
CANCEL
CANCEL button
MENU
OFF
ON
DISP
DISP switch
MIC
LEVEL
MENU SEL switch
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