PIR sensor plafond - bulb cycling on and off, how to fix?

I have a PIR sensor plafond fitted, model as pictured.

Unfortunately, the unit has been malfunctioning for some time: instead of the bulb switching off after a preset delay time, there are several cycles of switching off and on. The number of "flashing" cycles depends on the set delay time: the longer it is, the more of them there are.
The control circuit board looks like this:

Anyone familiar with this layout? Is it still salvageable or do I need to invest in a new plafond? I have tried replacing the electrolytic capacitors but without success.

If the module is faulty, it may be worth replacing the module itself to avoid buying the whole luminaire.

niewolno2 wrote:

If the module is damaged then it may be worth replacing the module itself to avoid buying the whole luminaire.

And do you know where you can buy a module that fits a particular luminaire? It's some sort of Swedish manufacture (that is, the luminaire, the module may be Chinese), as far as I know.

I have personally fitted a very similar module to a plafond that was bought by a client, so it seems that any module can be adapted taking into account safety issues related to correct installation. Check in lighting or electronics shops, this module was bought in castorama such was the information I received.