Dumb question for confirmation:
Can you swap a master drive from one player into another player and have it just work?

Answer??
Not unless both players are at the same EXACT software version, right down to the "consumer" and "developer".

Why:
I'm working on my questionable spare, trying to determine if the drive is crashed or if it's something else. One diagnostic was to use drive sled from my main empeg and connected it to the bad empeg.

Both main and spare empegs are running 1.03 (just because) and I thought I'd been told that I could just swap and bootable drive to any old empeg and it would work. But, the spare (with the other empeg's drives) gave me the on-screen error on bootup:
Starting mixer failed

Looking at this thread made me realize: my main empeg is running 1.03 developer and my spare is running the stock 1.03 consumer. Is that difference enough to cause that message? Thanks.

Yes, you can just swap the drives no problem. So long as the kernel (Hijack?) is up-to-date on both of them