I shipped a Technics KN-5000 to a customer and they're saying the "G,B,and D#" keys are not working across all octaves.

I understand if one set doesnt work which might indicate a hit or damage during transit, but the fact that the same keys don't work >>across the board on all octaves<<< seems kind of goofy and I was wondering if anyone might have any ideas what can cause this?

And what a possible solution may be?

Thanks!

Zalmang