I have a similar issue with samsung soundbar not connecting to there subs. It's really common when you google it. You can buy an random bluetooth speaker for a few quid and connect it to your phone no problem yet samsung have issues connecting there own devices.
Hi, I have a HW-J651 soundbar and a PS-WJ651 sub, and the sub keeps doing the same thing, flashing blue and red.
It worked yesterday for the first time in about a year and then went again. I spoke to Samsung and unfortunately they were of little help. I'm going to ring my local service centre tomorrow, failing that, a facebook plea to anyone locally to me who has experience with bluetooth connections wh may be able to help. I'll keep you posted!