Is there a way to Apple Repair an unresponsive ipad (won't turn on or chage) - without erasing it?

During repair, the iPad battery will be disconnected - and so doing will unavoidably reset the Secure Enclave (the iPad security chip) - within which the encryption keys, required to access all locally stored data, are stored.

If you don’t have a pre-existing backup, all locally stored will be irretrievably lost. However, any data synchronised with iCloud can be accessed by the repaired device.

For practical purposes, if “repaired” by Apple, in lieu of repairing and returning your existing iPad, you will likely receive a reconditioned/renewed iPad of the same model and specification.

warrenEBB wrote:

I'm asking: if i pay $250 for apple repair to "fix" - are they just going to send me a different ipad back? is it expected that they won't fix the ipad i'm sending in (with unique data saved on it).

Yes, that is correct. They will send you a replacement iPad.

+ is there any way to assert "do not erase"?

No. And, no legitimate repairer would ever say they can guarantee that data will not be lost during a repair.