I Can't Seem to Pair My HRM200 with Edge 1040

I replaced my heart rate monitor with the new HRM200.  It connected just fine with an Edge 1050, but my Edge 1040 finds the device, but doesn't successfully connect to it.  It spins for a minute or so, then says "maybe your device isn't in pairing mode, try again?"  I can't seem to get past that point.  Any suggestions?  Thanks!