Help please.

I use allways 2 psu for each of my S3. 1 psu for each blade. Lately one of my S3 turns of in the sideof the controler board. Today it happened again. When i went to take of the psu to check it it was melted and couldnt take it off without cut the wires.

I use the same model psu's for other antminers S3 and never happened that. I also cross green and black wire and never got problems with that.

Does anyone knows why this could happen?

Thank you.