Sorry to hear that.
Have they said what the damage is? I can think of many things such as blown internal traces, lifted pad, etc.
Again, this is why Bitmain Warranty (and Bitmain factory service) need to provide a report that says more than 'Fixed" or "Unrepairable"...
no they just told me it cannot fix
so i paid 300$ for 8 hours of hashing with 4.6THOuch! I just sent a board in to Denver and waiting to hear back. I think mine is repairable as it would hash great for a while then start to show xxx's and then stop. No high HW or heat issues from what I could see, just got tired of restarting the miner every couple hours.
Update on my repair. Got it back Friday and it is working great. The cost was $200 and they said it had a bad asic chip.