x68000 XVI screw, shield, PSU, and external/internal HD questions

[DMR]

So I've bought an XVI and an XVI HD. 
The XVI was opened up by the previous owner, 
while the XVI HD looks to be untouched since factory (I'm basing this off of how pristine the inside looked compared to the other XVI). 

After opening up both, I noticed some differences between them, 
and now I'm wondering if maybe both of them were opened up.

1 - Screws:
A - On the bottom board, holding the shield, there's two screws.



One's a slightly longer yellow screw and the other is the slightly shorter white screw. 

The XVI had the yellow screw on the right side while the XVI HD had the yellow screw on the left side.
So which is the original factory screw position?

I went with having the yellow screw on the right, because it had an additional metal plate to go through and thus it'd make sense for it to be longer.

But, the XVI HD, which I again assume is untouched, has it the other way around.

B - On the LED status board, there's three screw holes.

The XVI HD (which I assume is untouched) had one screw missing:


While the XVI had all three screws (but the middle one seems to be whitish, sorry for the blur, while the other two look yellow).


So what's the factory screw setup? Three or two?
The other thing about the XVI is that it had a screw completely missing from elsewhere.
I'm wondering if the previous owner mistakenly placed the screw in the wrong spot.

2 - Shield.

I don't have pictures of it but the XVI HD had a huge shield across the entire motherboard,
while the XVI itself didn't. The shield also had a window to place the FPU through.

Did XVIs ship with a shield across the motherboard? Or is this an XVI HD addition only?

I'm thinking whoever owned the XVI opened it up, and couldn't be bothered to reinstall the shield.

3 - PSU.

The XVI HD's PSU looks like this, and I'm wondering if this looks like someone worked on it or is it how it looks from the factory? The solder work looks ghastly...



4 - Is there a way I can have both and external and internal HD?
I assume I need to change the SCSI-id of the external one? Only one of them shows up during boot, the internal one.

[Spitko]

That PSU damage does not look normal. It's not uncommon to see some corrosion from capacitors leaking, but that looks to me more like liquid damage. Treat it like any other board corrosion case and clean accordingly. As for the "atrocious" soldering, you'll note most of the joins look fine; the ones that look awful are likely all electrolytic capacitors. It's SOP to replace these in any 68k as the originals are all bad. It may simply be the person who did your cap job wasn't particularly talented with an iron. That junk on the board could also just be shitloads of uncleaned flux.

Internal and external HDD should be fine. Just don't use the same SCSI ID, as you suspected.

AFAIK all 68ks had that shield, as it's mandatory to pass EMI. They're a total pain in the rear to get out, so your guess is likely correct; your previous owner decided it was too much trouble or mangled the thing getting it out, and so it's gone. Odds are it won't affect anything, though any EMI sensitive devices nearby might notice.

Your screws are likely just that: Misplaced and put in the wrong holes. There are several screw sizes and types, a rushed repair job may easily produce "spare parts". I wouldn't worry about it too much unless the board is loose.