Repair off/on switch Roberts Gemini 29 DAB radio CRD-29

First image shows general view of radio and faulty on off push button switch (yellow arrow).

Second image shows the radio with bottom removed after undoing 4 screws on the base. Unfortunately, to get to the internal faulty switch, a near full disassembly is required.

The 2 connectors on the power board did not readily come apart so I removed the power board itself by undoing 2 screws (green arrows). I removed the ribbon cable (blue arrow) and speaker connectors (pink arrows). To make room, I also removed the earphone board (1 screw -red arrow).

Note the front panel can now be detached by slightly bending the 4 white clips (yellow arrows).

Snip the plastic tie pull (orange arrow). It need not be replaced, unless the radio requires robustness (ie it's moved a lot).

With the tie pull removed, as in the previous step, the upper board can be lifted as it is only kept in place by the 2 long rows of pin connectors (orange arrows). This module can then be put to one side.

The main (largest) board can be removed by undoing 5 screws (red arrows- one hidden in image). Note this board is also held in place by a line of pin connectors (under the soldered in ribbon cable) so needs a little force (especially as the ribbon cable is a bit stiff).

In the above step, I also took 6 screws (green arrows) out of the front board for slightly more wiggle room, but it may not be necessary.

Turn the main board over and you can see the offending momentary on/off switch (red arrow). With electrical contact cleaner (I used 'Kontakt 10 Super') trickle a few drops down the black push button into the switch body and press the button about 100 times to clean the internal contacts.

If you have a multimeter, you can clip the probes onto the back of the switch to check progress. In my case, the resistance changed from about 300 +-100 ohms to less than 1 ohms ie the same as the other switches on the board.

If the switch cleaning is not effective, a new switch needs to be soldered in place (cheap eg 10 for £3 'Tactile Momentary or push button Switch 6mmx6mm 12V 4PIN' on eBay).

Note: I mistakenly removed the cosmetic shiny discs which were at the blue arrow location at each front corner. I had to glue these back on!