Yup, that sounds like a problem, and not one that we’ve seen before.
So, there are two basic possibilities. Either the microcontroller is running, or it isn’t.
If it is not running, that could be due to not being seated properly in its socket, or a bad solder connection at one of several critical points such as the crystal oscillator. Gently take off the LED digits and look at the bottom of the circuit board to see if you can see any signs of what might have gone wrong.
If it is running, then it is possible that through static discharge (or something similar) the LED driver chips were damaged, and are no longer producing lit LED segments.
Now, how to tell the difference? The alarm and rear-panel “nightlight” LED are independent of the LED segments, and should respond normally if the microcontroller is actually running– although it may be hard to navigate to the right menu places to test those. If you have a USB-TTL interface, you could also try reprogramming the clock (or simply communicating with it via serial) to see if it’s up and running. (You could also try reflashing the bootloader, if you happen to have an AVR ISP programmer handy.)
If all else fails, you might consider sending it back to us for analysis and/or repair– again, this is not something that we’ve come across before (unless it does turn out to be a bad connection, as it usually does).
