Hi, I’ve had a pair of R-15PMs for about 2 years now. No problems. Now, the phono input has crapped out. Worked perfectly before, but now only get sound out of the right speaker. Seems like a bad input or preamp? All other inputs work fine, Bluetooth, Aux. I’ve switched RCA cables, even hooked my iPhone up via an RCA cable. Not cool for these speakers to crap out this way with light use. They have been hooked up to a U-Turn w a preamp output. Speakers set to phono, not line. Speaker wire fine, of course. Any help?