Hi,
That error "USB Accessories Disabled: Unplug the accessory using too much power to re-enable USB device." looks really bad symptom. It may happens short circuit or serious fault somewehre.
I'd suspect USB cable or port first, though, the controller itself can be already damaged.
Did you try another cable or USB port?
A) At first, check where it works as USB keyobard.
1. Remove battery and turn off Bluetooth with the slide switch.
2. Plug into port with USB cable.
Does the LED turns green and the keyboard registers keys?
Also try Windows or Linux if you have any.
If not try another cables get from reliable source. There are many many bad cable in the market unfortunately.
Use cable comes with HHKB, it is enough reliable unless it is damaged.
If it doesn't still work, try reflashing default firmware downloaded from Keymap Editor.
B) Check your HHKB is still safe and work with its original controller.
Does the keyboard work well with the genuine contoller and the cable?
Dear Hasu,
I have had my hhkb pro 2 with the hasu controller for about a year. This morning the keys were not working but the green light was on and I was connected via a cable. Bluetooth also would connect, but keys wouldn't work. I tried restarting my computer and resetting my Mac's SMC and pram. Nothing changed. I came back after a few hours and tried again. With the cable nothing worked and I got a notice from my mac saying: "USB Accessories Disabled" Unplug the accessory using to much power to re-enable USB device. Next, I tried plugging the keyboard into a different power source and using bluetooth. The bluetooth didn't work unless it wasn't plugged in. With the keyboard connected to power and bluetooth on I was able to type a little and then random keys started to execute.
The keyboard has been on my desk for months, so I am doubtful it was damaged or spilled on without my knowledge.
I wasn't able to re-flash it, since when it is plugged in the computer didn't recognize it.
Any ideas on what to do next? Could I just need a new battery?
UPDATE: I removed the battery and the keyboard works with bluetooth, but not the cable alone.