That's about it, really - got a not particularly old Panasonic Blu Ray (cheapo home cinema thing, with half a dozen speakers plugged in the back, sub woofer etc) that has decided to spontaneously stop recognizing disks - displays a message such as "format not compatible".
It's always been a bit iffy, one day recognizing a disk, the next day not. I've stuck a cleaning disk in it a couple of times, which normally works, but nothing now.
Firmware looks all up to date. It's not expensive, and I can replace it, but I wondered if there's a trick to get this sort of thing working?