Power Circuit (Panasonic Q)
Still very much under reverse engineering still, below are my rough notes on the general power circuit of the Panasonic Q. Things may be wrong until I have worked on more units to confirm.
The AC power into the console comes in at the AC connector on the bottom right. It accepts 100V (so 110V mains like Japan and US) so if using it in the UK or similar you will need a transformer.

The mains AC travels through a 2A rated fuse, through some basic filters and capacitors off to the rest of the board.
The left of the board has a power connector P that goes to the top lid board.


There is another 3 pin connector K with a ferrite bead on the cable, that sends 8V and -8V to the side board.


The thick black and red wires on the AC power board sends AC power to the DC Power Board, along with the 5 pin IDE cable wiring on the bottom left.

Power comes from the AC Power board via the 2 thick wires for AC.

IC | Identifier | Notes |
---|---|---|
IC904 | 2903 1119K | Probbaly LM2903 Comparator |
IC905 | 9743A | BA9743AFV 2-channel switching regulator controller |
IC906 | 1150S | IR1150S uPFC One Cylce Control |
IC907 | 1150S | IR1150S uPFC One Cylce Control |
Q906 | 6912A | onsemi FDS6912A Dual N-MOSFET |
Q907 | 6912A | onsemi FDS6912A Dual N-MOSFET |
All of the power to the DC board comes from the AC boards 2 pin AC input, which is switched on via the large relay, which is turned on when the front board sends the power on signal to the AC board to turn on that relay.
After that, the DC board sends back 5V, -12V and 12V to the AC board.
From left to right it is 5V, Ground, -12V, ??? (ground), 12V.
The fourth pin connects to ground, but I think through some inductor or shorted passive, so it isn't directly ground as such.
The 12V (pin 5) is joined directly to the Connector N to the left pin (pin 1), as well as going to the 2-pin 12V black/red wire in the middle of the board.

The DC board also outputs 12V, 5V and 2.5V rails onto the side board from connector N (from left to right, far right being ground), when the Front Board (powered by the Top Lid, powered by AC power boards connector P) sends the Turn On signal to enable the large relay on the AC power board to send power to the DC board.

Power to the GameCube Power Board that sends power out to the GameCube via the 2-pin cable when powered on. This is 12V DC.

The sub-board that receives 12V DC power from the DC board (connector M), and passes it to the GameCube console (connector L) when it is switched on through the AC boards relay.
It also has another 4 pin supply (connector J) that goes to the Side Board.

The 2 pin wire (connector U) sends power from the side board to the system chassis fan.

The power to the optical disc drive coms from connector O which comes from the Top Lid (and the power to the Top Lid comes from connector P going to the Side Board).

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