Hi bro,
Just got my camera back today, took them a total of 1 month and 1 week to get it back. Camera seems to be working fine, even with a fully charged battery and the battery grip. All seems well.
I asked the tech what was the problem that Japan side reported, he went to check and said that it was just some CMOS cleaning and touch-up, said Japan never replace or do anything drastic to the camera. Well the camera seems to be working fine for now. But I don't know if Japan really did not do anything more than just cleaning, else why would it take so long to get the camera back, unless most of their technical staff was on vacation.
I am thinking the problem actually might take shorter than the duration i sent my camera in and maybe Japan side was trying to consolidate a build shipment before shipping back to Singapore. But my suggestion would be to send in the camera for repairs. I don't know if anyone knows what the actual problem is or how they are rectifying the problem, but I heard and feel also that if you don't get it looked at and the problem persists, the shutter may just as well die altogether. Just my 2 cents tho.
Hope this helps whoever is suffering from the mirror flopping issue. Also seems that most of the people that suffer from the problem have had their cameras used in places with difference climates.
P.S: They will also update your firmware if you have a version lower than 1.11