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--- blog:commodore_c64_dtv_hacking [2023/01/31 10:24] – [Commodore C64 DTV Hacking] john
+++ blog:commodore_c64_dtv_hacking [2023/01/31 11:29] (current) – [Power Supply] john
@@ Line 64: / Line 64: @@
 ==== Power Supply ====
-The DTV normally gets ~6v from 4x AA batteries in the joystick. But also has a red LED connected which regulates down the supply to the 3.3v circuitry on the PCB, as used by a number of the chips. If the DTV is removed from the case and original power switch and LED, it is important that a LED is refitted to remain as a regulator.
+The DTV normally gets ~6v from 4x AA batteries in the joystick. But also has a red LED connected which is used as part of the regulator circuit to reduce the supply down to the 3.3v circuitry on the PCB, as used by a number of the chips. If the DTV is removed from the case and original power switch and LED, it is important that a LED is refitted to remain as a regulator.
 //Note: The LED should have a **forward voltage** rating of **1.8v**.//
+=== Power Switch Wiring - DTV 1 ===
+On a DTV 1, the power switch is wired as follows:
+{{:blog:c64:img20230128171536.jpg?500|}}
+Note that the (black) ground wire is soldered directly to the battery tab (the - terminal). The floating (red) positive wire is soldered to the battery tab (+ terminal).
+=== Power Switch Sub-Board ===
+A more detailed image of the power switch sub-board:
+{{:blog:c64:img20230131102833.jpg?400|}}
+From left to right, the connections above are:
+   * LED - (~+3.3v return to PCB)
+   * LED + (+5v from PCB)
+   * VDD + (+5v to PCB, connected by switch)
+   * VCC + (+5v from battery compartment, connected to switch)
+Seen from above, and with the plastic cover removed, the power supply sub-board also has markings to indicate the connections:
+{{:blog:c64:img20230131103754.jpg?400|}}
+In summary:
+{{:blog:c64:c64_dtv_v1_psu.png?500|}}
+=== Power Switch Wiring - DTV 2/3 ===
 ==== Joystick Port 1 ====