I have a tmo dual sim note3, and the GSM slot is super slow 2G. I have two old TMO GSM android and windows phones that both have 4G. Is it possible to swap them, I know how to solder but are they compatible?

I didn't find a conclusive answer about this in forums.
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Hey please help me, i m using this phone in oman under #Nawras network. Everything is fine, but only i cannot use 3g . Here sometime find the low signal of 4g and then direct throw me to gsm. And i discover that even im in hspa and hsdpa net, it will show the 4g icon in the statusbar. Pls help me about that. Many many best wishes to you all

I used to have a Note-3 N900 model (TGY - HK) variant and recently the motherboard was water damaged and i bought a replacement board from the local market and got it installed by the seller as i didn't have time. The new installed board read NULL/UNKNOWN for both the baseband and the IMEI so i decided to install the original firmware again to see if it fixes the problem.

I flashed the stock firmware for the (TGY-HK) variant from Sammobile but unfortunately the process failed at the end. I tried again and again it failed.

Now i am stuck, i don't know what is the variant of the new motherboard installed.

So my question is that, are there any roms that would work on all N900 variants? Also if i disassemble the phone would i be able to detect the motherboard variant from a code or something printed on it?

Thanks in advance.