[Endoperez]

Never-healing magic beings, such as most mechanical beings, are automatically repaired whenever they are brought to a lab. Just imagine the "wound" is the mysterious problem the computer repairman never manages to fix, and claims can't even exist. "Yes, sir, it's in full working condition. No problems whatsoever. I didn't even notice any of the symptoms you described, but since there's nothing wrong with it, it should work just fine."