Philips PM 5125 Manual page 25

29
In order to pull out the two other plug-in printed wiring boards, they,
should first be slightly bent. Furthermore, four wires (see Fig. 12) should'
be loosened before removing the oscillator board.
Note: When mounting the oscillator board, make sure that the four
wires from potentiometer RI are connected to this board in:
accordance with Fig. 23.