A7III humidity damage

[Mikael Klasson]

Hi Sony users! Recently my Sony A7III have started to act bad. I cannot access anything in the menu, when I press meny, change ISO, change F-Stop or viewing pictures nothing happens. 
Taking photos and adjusting shutter speed works fine. 
after leaving the camera for 2 days with no battery it worked for 20 minutes than the issue appeard again. 
The issue itself appeard after I came home from a photoshoot outdoors in minus 2 celcius. The guy i Spoke witg on Sony said the main PCB might have been damaged by humidity and the camera needs to be sent for a service, only the troubbleshooting alone is €110, plus the repair needed to solve the issue. 
My question is if any of you have had the same issue and if there is anything I can try myself to solve it? 
its 11 days since this happend and the camera still does not work so I give up the fact that it will solve itself by letting the camera "Dry".
I also think about the battery, if it would be an idea to try another battery, in case the humidity issue has damaged the battery and not the camera? I dont have a extra battery to try with and it feels risky to buy a new battery if thats not the issue. And would like to know if there is anything I can do before sending the camera for a repair. 
Best Regards, Mikael from Sweden. 

[FunWithCameras]

About humidity. The big risk is when you bring a camera which is cold (eg: has been in -2C) into a warm environment - you may get condensation from the warm air.

The advice I was given was to have a ziplock plastic bag handy. Put the cold camera in the bag when it is in the cold environment, bring it into the warm, and let it warm up without it touching the warm air. When it is warm, take it out of the bag.

You could try putting the camera in a container with a desiccant gel, but I doubt it will help now - the humidity may have done permanent damage.