Hi! I've encountered a problem when've been calibrating my sensor in CIT. My phone passes every test, but when I get to the "Put the FLESH CHART horizontally" the log shows that "KB CALIBRATION Test Failed". I searched for solutions, but the problem is that I never saw a person with "1515 Brightness instable" error. What does it mean? What should I do to fix that? I used fully black and white paper sheets. Before deleting the previous fingerprint, it could read it and showed a password...Read more