Power Supply; Board Access; Circuit Operation - Sony DSC-S75 Training Manual

5. DSC-S75 and DSC-S85 Power Supply
Chapter 5 - DSC-S75 and DSC-S85 Power Supply
The DM-101 Power Supply board converts the dc input from the ac adapter or battery into all of the necessary ac
and ±dc voltages.

Board Access

The DM-101 board is sandwiched between the SY-68 board and the front of the camera and is not easily accessible
for live troubleshooting.
The output and control lines to the board can be checked at CN701 on the SY-68 board when the camera back
is removed. Although the camera will not operate properly with the back removed, the power supply will power
up. The picture shows the location of CN701 on the SY-68 board.

Circuit Operation

Figure 5-1 shows a block diagram of the power supply board. Due to limited access, "live" troubleshooting is
limited to the CN701 connector on the SY-68 board. Therefore, the circuit description of the DM-101 board
will be limited to a block diagram.
With the exception of an unregulated always-on voltage and an unregulated battery voltage, all voltages are
produced by discrete switching circuits on the board. The switching circuits are controlled and regulated by
DC Control IC001, which provides the switching signals and feedback control to the switching transistors.
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