I'm cabled correctly, internal jumpers checked multiple times. All sound card selections made as per the SignaLink manual and their website. And all the levels set as per recommendations. The SignaLink came from a friend who used it successfully but found he cared little for digital modes. So I know it was once working. #1..I can only see and decode signals when the interface is powered off. Turn it on and signals disappear. I can hear them thru the rig's speaker but they disappear from the waterfall. BTW---SignaLink is going into the rear accessory port of 756. I've looked and re-looked at internal jumpers(SignaLink--made sure they're configured for 756Pro), double checked my cables into acc port etc. Clock is kept accurate by Dimension 4 btw. #2..This seems to be even more curious. When everything is powered up for the first time...computer, rig, soundcard......on the first tx or use the "tune" function within WSJT-X program the output will go to whatever power level I have set (evidenced by outboard meters) and immediately fall back to zero even though the rig is still in keyed mode. Just no audio going into the transmitter hence no output. I can then hit tune or enable tx and it will not show power out even though rig is in tx mode. Power cycle everything again and it will act the same way. Anyone have any similar experiences or offer some direction? I'm running out of ideas.