Why am I getting a red x for apple support?

I have a refurbished modified ipod classic, I believe it is a 7th generation with all new parts. I've only had it for a few months. It has a 512 gb flash solid state drive which worked perfectly until I dropped it. Now all I get is a red x apple support logo. I tried resetting it but it didn't help.I opened it up but can't tell what is wrong with it. Everything seemed to still be connected and in place. What should I look for? Is the drive damaged? I paid a hefty price for it and figured it would survive a fall of 3 feet. Aren't flash drives supposed to be more durable than hard drives? I don't remember how long it was guaranteed for and don't have the seller's contact info anymore.