need to find switch to keep Canon S90 on with external adapter

[Al Stuill]

Recently purchased a used Canon S90, a couple of batteries and an AC
adapter as well. I'm running into an issue while trying to use the AC
adapter that I'm hoping someone can address. The only way the external
adapter will power the camera is if the battery door is closed. If I
plug the adapter directly into the Canon adapter (dummy battery) and not
through the door (battery door opened), the camera won't come on... but
I need it to so I can easily change out SD cards while the unit is on a
tripod. There must be a switch somewhere that closes when the battery
door is closed and allows operation, then opens when the battery door is
opened. Can anyone tell me the location of the switch? Thinking a
small toothpick might be able to keep the switch active and the camera
powered... at least that is my hope.

Thanks in advance.