kind of late to the party, but if anyone would like to see two PAL VA1's side by side with different drives and some other different make parts, here you go. Both drives are 3.3V though.
Note the metal fan frame vs the plastic fan frame.
One of the drives didn't work, thankfully i did not swap them, instead i gave it a good clean, disconnected everything and reconnected, tweaked the potentiometer ever so slight and that go it working again.
I got the second faulty one to swap out the bottom shell to my main dreamcast (which came with a xilink chip region mod).
But i didn't swap any electronics.
It's something important though, replacing broken components, always check, always verify, you never know.
The broken video issue on it (which i made a help request-thread for) taught me to be careful when connecting faulty electronics to screens, there might just be a fault that can damage whatever you connect it to. It never crossed my mind, until i saw that damaged diode on the board.
And thanks to this forum i read this thing actually plays a role in (well, external) surge protection.
check it before you wreck it