BTW - what I wrote was a bit vague. LVD will work if it is used with a proper terminator. It won't work at all if it's the kind which doesn't switch to single ended (which is rare). Some HVD have switchable drivers (also rare; talking about bus drivers, not software drivers, BTW), but if the drive doesn't have that option, there's no way it will ever work and may break things (magic smoke escaping is certainly possible).

The simplest configuration is to get an SCA to 50 pin adapter with termination built in, then connect it to the internal bus using the internal cable. The external enclosure and adapters add a lot of variables.