Yeah, chances that cables fail are much higher than electronics. The first I do in those cases is to swap the left and right connections to find out if the problem moves with the swap or not.Well, I guess I'm getting too old and messed up. Being pretty sure that that front left channel was out on my 5200, I picked up a 4700 and sold my 5200 on Ebay for "repair or parts". Afterwords, I received feedback from the buyer that it "works great". So, I contacted the buyer to confirm that the front left channel was working and he said he's using the pre-out and, yes, it works. So, I guess I failed to detect some problem with the interconnect cable connection to that pre-out on the 5200.