Navigon 40 Sat-nav with no sound coming from the speaker.
4 small torx screws keeps the cover in place (yellow circles).
Pry the front and back cover apart, using a "soft" tool. The tool I'm using is made out of plastic.
Lift the plastic "lock" (yellow square) in order to remove the flat display connector.
2 plastic hooks (yellow circles) keep the PCB in place. Push them outwards.
Lift the speaker connector (red circle) and the battery connector (green circle).
2 Phillips screws keeps the speaker in place (yellow circles).
Remove the speaker.
I used a standard 28 mm, 8 Ohm, 1,5W speaker which I put back in place using some black silicon.
I had to swap the old cable and connector to the new speaker by soldering (green circles).