I inherited a switch stack consisting two Cisco WS-C3750X-48T-S switches to which I'm trying to add two more switches of the same make and model (also I downgraded these two newer switches to an older image version so all four switches match). However my attempts to join these two new switches to the stack has failed. The current switch stack does not see the new switches. I ensured my StackWise cabling was correct by following the documentation linked below but still no success.
The two new switches are not seen by our current stack, and oddly enough these new switches formed their own stack so now I have two seperate stacks instead of one. An attempt had been made earlier by another tech but the images weren't the same between the older and newer switches, so I wondering if this initial failed attempt may be preventing the switches from joining the stack. An troubleshooting ideas are definitely welcomed. Thanks!