Installation of the 12c508 4-wire Mod
for a PU-20 PlayStation
Removal of the PSX cover
- Turn unit over and remove the 6 screws.
- Turn unit right-side up, and lift the cover off.
Removal of the laser housing
- Disconnect the flexable PCB by pulling straight up on the black connector. This will release the board, which can then be removed, by pulling straight up.
- Disconnect the power connector (3 grey + 1 white wire) by pulling straight up.
- Lift off laser housing.
Removal of the controller/memory card housing
- Remove the two screws.
- Disconnect the ribbon cable by pulling straight up.
- Lift off the controller/memory card housing.
Removal of the heavy metal bracket
- Remove the 5 (?) screws holding the bracket in place.
- Lift off the bracket.
Removal of the circuit board
- Remove the 5 screws along the top edge.
- Lift off the circuit board.
Mounting the chip
- Carefully bend the the pins of the chip so they are parallel with the chip. Now when the chip is placed right-side up, the profile is much lower.
- Locate the site to install the chip. It is located on the underside of
the mainboard near what would be the front right corner of the board when
the board is normally oriented.
- Insulate the chip from the main board. I attach a piece of electrical tape
to the board and place the chip on top, then once the whole process is
complete, put another piece over the top of the chip, insulating it from both
board and shielding.
Making the connections between the chip and the PSX PC board
Relevant pins of the 8-pin 12c508 chip
With the chip right-side up and the notch at the top, pin numbers are read
counting down the left side from 1 to 4, and up the right side counting from 5
to 8. Pin 8 is located directly across the chip from pin 1.
1 - Vdd
5 - Gate Wire
6 - Data Wire
8 - GND
Pin 6 -> Data Wire
Connect to #7 in the next illustration.
Pin 5 -> Gate Wire
Connect to #8 in the next illustration.
Pin 8 -> GND
Connect to #5 in the next illustration.
Pin 1 -> Vdd
Connect to #14 in the next illustration.
That's all there is to it. Be sure to insulate the chip from the metal plate on the bottom of the PSX. Now, just reverse everything you did to take this thing apart,
and you're done. Fire it up and play your imports without having to swap ever again.