Phone A is having issues connecting to data and phone networks, so I checked the ROM on Phone B (which works great), downloaded it, and flashed Phone A to that ROM. It still doesn't work.
I was going to swap the motherboards (Phone A body is mint, Phone B has a few nicks), so I could sell the mint one fully working, and the nicked one as not working with software issues.
When I opened them up, I found that Phone A has a stacked sim/sd card reader, while phone B has two separate reader slots. Of course, the motherboards couldn't be swapped because of that.
Both stickers say i9100GSMH, and the IMEI's match the stickers.
So, are these different versions of the same phone? Is phone A (with stacked card reader/sim slot) some other variant, that requires a different ROM?
Also, in looking at Phone B's motherboard, I-9100 is clearly stamped on one of the heat shields in the working phone. The non-working Phone A doesn't even have the same heat shields on the motherboard.
So, what is Phone A (double stacked sim/sd, no stamps, won't connect to networks).
The ROM for both is stock XWLSW, with XXMS2 baseband.
In the pics below, Phone A (suspect) is on the left, and B is on the right. The close up is of Phone A.