Somebody brought me an iPod with the timeless White Screen Of Death. That used to be pretty common and is easily fixed by reloading the firmware.
It worked, I turned it on, and things got a bit weird.
Somewhere along the way, about half the letters in every bit of text in the firmware vanished. Some shorter words had the misfortune to disappear altogether.
I have no idea why this happened. The firmware copy was fine, the loading process was fine, and if it was general corruption we'd be seeing a lot more than just missing letters.
Sadly, reloading the same firmware a second time gave me a perfectly-working iPod. Sometimes things are more fun half-broken than working.