Hi why my secod gpu dont mine ?!
If you swap them does the problem move with th card or stay with the position?
If it moves with the card the card is jacked. If whatever card is in that second slot stops working then the pci slot is not set properly (or broke)
Do you have all the power connections connected? Reseat all the connectors (disconnect, inspect, confirm proper connections, reconnect) both ends. Make sure the power is off of course.