This just happened to me as well. I purchased a Blue right when they were announced ~18 months ago and last week the USB ports died (taking down my Zigbee and RT-SDR USB sticks.)
I ordered a replacement from HardKernel and it arrived pretty quickly from South Korea. I first tried a new power adapter with the original Blue, but the USB ports still did not function.
I shutdown the Blue, swapped the motherboard and memory chip, re-assembled, updated my DHCP lease to accept the new MAC address, plugged it in and it started right up again.
It made me think about having replacement hardware around for situations such as this. I’m going to get a Home Assistant Yellow box and see how that performs. I’m not sure how much of an upgrade it will be (other than ssd support and a new zigbee chip) over the Blue. It’s not clear if the Pi CM4 performs better than the Odroid chip or not. Whatever I end up using longer term, I think I will order a backup set of hardware to have on site… just in case.