Hello, my name is Bernhard.
I recently bought a BV8000 as a motorcycle navigation system. In order to check the waterproofness I sunk it into a bucket of water for about 20 minutes. When I took it out and it worked for a while. Suddenly the screen flickered and it just crashed.
Then I screwed it on and found that there was water inside. I dried it and reassembled it. Then I wanted to know where the water got in. For this I put my lips on the case, where the top and bottom meet and tried to suck in air. On the upper side (where the brightness sensor, camera etc. is located) I could suck in air without any problems.
I then disassembled the device and looked at it again. Either the edge that presses into the sealing rubber is too small or the sealing rubber is too deep, so that the edge cannot exert enough pressure on the sealing rubber. Thereupon I applied sealing compound (Hylomar or similar) additionally on the seal, let it dry slightly and reassembled it. Now I couldn't suck in any more air at this point. Then I repeated the water test and no more water entered.
Since I wanted to know if I had gotten a monday device or if there was a production error, I bought a second BV8000. Also at this one I was able to suck in air at exactly the same place (at the whole upper edge of the housing) again without any problems, so that also this one is not waterproof.
Which of you have actually left your phone in the water for a longer time? Can you please check your BV8000 if you can suck air at the upper edge of the case without problems?