Why not just buy a replacement motherboard for about 18 dollars on Ebay ? If you have a 9010, make sure you get a 9010 motherboard. Same for 7010. The BIOS is slightly different for each one. You should be able to keep using the same SMBIOS info for your system no matter which approach you take.
Should I do the same installation for the new set with the replacement motherboard? Or the real question is, does the apple-id-registered SN depend on the motherboard SN or not?
Just connect up your SSD and it will work as long as it's the same board and form factor i.e. 9010 MT if that is what you have now. On Ebay look at the pics. Each MT board (7010 or 9010) has 4 sata ports, the DT boards only have three. That's the only real way to tell them apart. Check with the seller to know exactly what you'll get.
I really don't know for sure if it matters to Apple, if that gets checked by their servers. Give it a try as is and see if all Apple services work or not. The board serial numbers we generate are not real Apple serial numbers anyway. Generate a new one if you'd like, it shouldn't make any difference. I know you can replace a genuine Apple board and keep the same Apple ID registered serial #.
Did you rule out a possible dead CMOS battery first ? When booting UEFI and that battery fails you will get a black screen, no BIOS either. It looks dead but just needs the CMOS battery removed and replaced. It's discussed in the main guide. If you try to boot and the fans still spin, this is usually what it is. If the mobo gets no power at all then it is likely to have failed.
Thanks for your reply. The board was water damaged. Luckily, I have several sets of optiplex 7010 from a broken company.
Update from what to what ?
