I have flashed a few K800i phones with K810i R8BF003 software. One was CID52 and 2 others were CID53. One of the CID53 phones flashed white screen after debranding. It was a new phone, the others were old. I have found other websites that say newer K800i phones have a newer LCD which does not work with K810i firmware. Check to see if your phone is relatively new (less than a year). If it is flashing white then you cannot use K810i software on it. You can recover your phone by flashing it back to the K800i software. This is what I had to do with that new K800i.
Darren