Help Flashing an already locked phone

[ChronoTheChangeling]

So I have been looking into flashing my current note 20 phone. I purchased it unlocked but it still has the AT&T firmware on it. At first I thought it was no big deal but I've had it for a while and see that I am still on Android 10 while everyone else in my family is on Android 11 or higher. I have MetroPCS as my carrier right now and am wondering if I flash Tmobile Firmware (I can't seem to find fully unlocked firmware) then will it still work and not brick the phone?
The phone is unlocked already from AT&T and I've been using it for almost 2 years. I would like to update it soon but I wasn't sure if flashing to Tmobile would brick it.

 

[ocnbrze]

What is your model number?

 

[ChronoTheChangeling]

What is your model number?

SM-N981U

 

[ocnbrze]

try just flashing the unlocked firmware:
https://www.sammobile.com/samsung/galaxy-note-20-5g/firmware/#SM-N981U

no need to flash other firmwares from other providers. those firmwares would be device specific and could cause issues with your phone.

i have an unlocked z fold 3 that is on verizon, but it is not on verizon bloat on it.

 

[ChronoTheChangeling]

try just flashing the unlocked firmware:
https://www.sammobile.com/samsung/galaxy-note-20-5g/firmware/#SM-N981U

no need to flash other firmwares from other providers. those firmwares would be device specific and could cause issues with your phone.

i have an unlocked z fold 3 that is on verizon, but it is not on verizon bloat on it.

So pulling up the site which I was looking at before It only has a few options. My question then is all the firmware on the site unlocked?

 

[ocnbrze]

you are right the t-mobile unlocked version might work.....but why would you want that? it will have t-mobile junk on it. my unlocked z fold 3 is on verizon, but only because i have the sim card for verizon in it. there is no verizon bloatware installed on mine. if you want t-mobile crap on yours by all means go for it....lol

 

[ChronoTheChangeling]

you are right the t-mobile unlocked version might work.....but why would you want that? it will have t-mobile junk on it. my unlocked z fold 3 is on verizon, but only because i have the sim card for verizon in it. there is no verizon bloatware installed on mine. if you want t-mobile crap on yours by all means go for it....lol

Well right now I have AT&T bloatware and no option to update past android 10. I don't see a just unlocked with no bloatware so I thought going with the carrier closes to mine that still allows updates would work. Am I right about that?

 

[iBowToAndroid]

unlocked with no bloatware

"Unlocked with no bloatware" would be N981U1. Switching between U and U1 does require a factory reset though

 

[ChronoTheChangeling]

"Unlocked with no bloatware" would be N981U1. Switching between U and U1 does require a factory reset though

OK I have my phone backed up but which version of the U1 firmware should I get? The XAA? Also how would I go about doing that. Every guide I seem to find is for the Ultra and on top of that I'm not sure what to do with this phone. Last time I buy an ATT unlocked phone.

 

[ocnbrze]

curious match your baseband with the PDA that is on the list. which firmware does it belong to?

 

[svim]

I'd recommend you should just use a ROM that specifically matches your model I.D. Every phone model has it's own unique hardware configuration and every ROM is specifically and intentionally tailored to correspond to each phone's hardware. Android ROMs are not the same as something like a Windows Install disc/media even though a lot of people mistakenly assume they are -- in other words, Android ROMs are device specific while a desktop OS Install disc can be used on huge variations of hardware.
If you do want to experiment with using a different ROM than what matches your phone, there is a chance that'll work out for you. But it's more likely you'll just soft-brick your phone so it gets stuck in a boot loop, and in that case you should be able to just re-flash using the correct ROM to restore your phone back to working condition again. Keep in mind that hard-bricking your phone with a ROM mismatch is a possibility but not as likely.