ColorMFA

Recently, a customer reported to me that his ColorMAF is abnormal and the LCD screen cannot display properly. He handed me the meter for inspection. As the customer described, I connected the power supply for testing. The measured input voltage is 12.07V, but the LCD screen only lights up a little and does not display any information. Later, I replaced the LCD screen with a new one, the situation is still the same, how to solve this problem now? Has anyone else encountered a similar problem? Can anyone give me some suggestions?

Did you connect the Ignition wire from ColorMFA to +12 during testing ?
Please make a video/photo if possible..

I have already emailed you the photos and videos of the test process, please check the email(ru), thank you