This time a bit of a more technical article on the Ericofon chassis. From time to time I get some questions on the big red button on the bottom. The problem often is that it will not come out, or come out slowly, once the phone is lifted. This will end up in a call that will be answered late after picking up or not at all.
Above you can see the way to remove the red button.
When you take out the chassis from the shell you have to make sure you have access to the situation in the first picture. The red circle in the middle locates the top of the red button. The example in this picture is a Dutch PTT chassis with the typical PCB on top which needs to be removed by the 2 screws (note they do not have equal length).
When the oval hole as in the second picture can be seen, you need to put a small screwdriver inside it. Carefully drag the screwdriver slowly in the direction of the arrow so that you take the upper metal strip with it. Approximately 0.5 cm (0.2 inch) should do. The red button will be released.
You will notice that the pin attached to the red button is dirty and should be cleaned and lubricated again. This secret will resolve your issue. 😉
Other chassis might have different layouts of PCB’s, ringers or capacitors that are in the way. But the principle of locking and unlocking the red button is exactly the same for all chassis.
Note: For the more advanced engineers: you can also unlock the red button from the side of the chassis. Position the screwdriver carefully on a ridge of the metal strip you want to move and push it forward. It will work and it is sometimes attractive to do so. But you have a 99.9% chance you just ruined your complex and vulnerable switch with all contacts without noticing. So do not use this method.