I really didn't drop it that hard. Knee level to floor. It's had a lot farther falls than this, and onto much harder surfaces. But it landed at an angle that cracked the upper right corner of the lens, and cracked the fascia a little bit.

Player works, boots, looks fine. Network works, songs play (when controlled by EmpegFace), no hard disk trouble. But the buttons and knob don't work. IR does not work either.

Dismantled, made sure nothing internal was bent or broken. Display glass still A-OK.

The connector that joins the display board's ribbon cable to the motherboard was slightly bent, as if it had been bonked by something, except there isn't really something that could have bonked it. Perhaps the hard disk tray flew forward hard enough to yank on it. Anyway, bent those pins back up straight (very gently) checked connectivity, checked the three nearby fuses (all good), touched up the solder joints where the connector meets the motherboard. No help.

I once had a problem where the PIC next to the buttons had a cracked solder joint at pin 1, so I retouched all solder joints on both of those PIC ICs on the display board. Touched up solder joints at the display-board's end of the display ribbon cable. Touched up a few other solder joints on the display board that were easily reachable. Still no dice. Checked connectivity of all pins on the display cable, testing connectivity from the motherboard to the display board, they're all good.

Please note that this is a fully dismantled player, with the display cable connected but the display board removed from the casing. Just to make sure it's not fascia sticking or case flex or anything like that. Another trick is that the Hijack menu should still respond to a longpress on the knob button even if there's no hard disk connected, and when I try that, the longpress does nothing.

Stu, Rob, anyone else... What are the most likely points of failure with these symptoms? Perfectly working player, even the illuminated buttons are working fine, except pressing the buttons, turning the knob, and sending IR commands don't work.

I'll post this then go look if there's anything funky in the boot log and follow up here if that's the case.