The customer has reported issues with these two orders and now they require us to provide the original factory's COC for the ordering side to inquire about
The problem is as follows: The customer soldered two models together on the board and cleaned the surface of the oil stains with acetone. However, it was found that the silk screen of lm2990t-12 on top had completely disappeared, and the silk screen below LM2940T-12.0 was still present 
