From SMA support:
6468: Overvoltage Boost Converter Input A
6469: Overvoltage Boost Converter Input B
6470: Overvoltage Boost Converter Input C
6488: Overvoltage Boost Converter Input D
6489: Overvoltage Boost Converter Input E
6490: Overvoltage Boost Converter Input F
Recommendation for any of these is to check the DC voltage on the applicable input to make sure it doesn’t exceed the max rating. Otherwise, you’re probably gonna be doing an RMA on a part.