first you can try a factory reset:
if this doesn't help you can try to recover the firmware via TFTP presuming the POST boot loader does still work, see: https://www.digi.com/support/knowledge-base/the-portserver-ts-unit-will-not-boot
this knowledge base also works for Digi One SP.
If it's still dead you might return it for repair in warranty. Warranty is 5 years (e.g. check the 4 digit date code near the CoO label it's year and week YYWW. Also provide it's MAC address to Digi Technical Support for warranty checking.