samsung galaxy a21 sim question

[corvairbob]

i have the a21 and the sim tray has the sd card open section and then a sim section closed and then a sin section open. what i would like to find out is if i was to put a double sim tray in this phone would it pick up the 2nd sim and let me use the phone as a dual sim phone?

i have metro pcs and tracfone plans. i had the tracfone plan for 15 years and this past month the wife got a free line from metro pcs so i put that sim into my a21, but that line has been turned off now 4 times in the past month for one reason or another. i found out that if she does anything to her paid line then the free line gets turned off and she has to call metro to get it turned back on, so i would like to get a dual sim phone and keep tracfone for maybe a year to make sure the metro sim does not get turned off again, if it does then i will ust leave it off and go back to tracfone. i do not want to just leave tracfone until i prove out metro will leave the free line up and running.

so if the a21 phone i now have can work with a dual sim tray i will get one and set this phone up for both sims.

 

[mikedt]

Inserting a dual-SIM holder into a single-SIM phone? I'd say it won't work, because the US variant Samsung(that are single-SIM) won't have the necessary contacts and provision for recognising and using a second SIM(SIM2).

But you could always obtain a dual-SIM tray for your A21 and try it, it will fit and probably won't do any harm in trying. Because both the single-SIM and micro-SD tray, or SIM1 and SIM2 or micro-SD tray are the same physical dimensions.

But I do think it won't work, not in a US variant Samsung phone.

FYI apparently some US variant Samsungs can use a real SIM and an e-SIM in the same device, and both may work. We had reports of a US variant S21 that could do this.

 

[corvairbob]

thanks i may get one but i will see if anyone may have did this. it is easier than carrying 2 phones or having 2 phones handy. i asked the metro forums if i can expect that free line to get turned off just because again and will see what they say. i could put it back in the phone the store put it in but then i have to have 2 phones close by. so having a dual sim would make this a lot better.
thanks

 

[svim]

A SIM card and microSD card are two different cards, they are NOT interchangeable. Simply because a dual-SIM tray and a SIM-and-microSD tray have similar dimensions, all that means is both trays fit into the same slot in the phone. The metal contacts that a card has and the metal contacts in a phone have to match up with each other exactly, and the internal wiring in each type of phone will also vary accordingly. A SIM card only retains a user's cellular service account data, it's used to authenticate the phone to use a carrier's cellular network. A microSD card however, is used only as a data storage media. So two cards with two different purposes -- you can't force a SIM card to be a microSD card, nor vice-versa.

 

[corvairbob]

yes i know that i was just wondering if by chance my phone migh be a dual sim if i was to put a dual sim tray in it with 2 sim cards? like maybe they all ahve the ability but if you pay for a single sim they put i single sim tray in them if you pay for a dual sim they just put in a dual sim tray. it may not be the case. i have seen things that were actually the best but if you paid a bit less they omitted some of the features and if your looked around you could actually by the parts to make them the best again. thanks

 

[svim]

If you take your SIM card and your microSD card, and put them both next to each other you'll see that they're different as far as shape and dimension, and that the metal contacts differ in number and location. Now visualize your phone's card slot -- the corresponding metal contacts have to be located to be in the exact same location when you have the tray inserted. A SIM card isn't going to fit into the tray's microSD card spot, nor will any of the contacts line up correctly if you do manage to jam it into place. There is no magic way tor a phone to move its own internal components to different locations, the slot is soldered permanently to the logic board.
You need to get a dual-SIM phone order to do what you want, or a phone with dual eSIM support. It's not just a hardware issue either, when your phone doesn't support multiple SIMs, more than one SIM card isn't going to work anyway. If the installed firmware doesn't already include dual-SIM support, it's not an option.

 

[mikedt]

You need to get a dual-SIM phone order to do what you want, or a phone with dual eSIM support. It's not just a hardware issue either, when your phone doesn't support multiple SIMs, more than one SIM card isn't going to work anyway. If the installed firmware doesn't already include dual-SIM support, it's not an option.

Apparently the US variant Galaxy S21 can support a SIM and e-SIM at the same time.
SOLVED - S21 - Network Provider does not show up
This was with an AT&T e-SIM and a Globe international SIM.

Of course i don't know if that will work for the US variant Galaxy A21 phone. Also one needs a carrier that can do e-SIM activations.

 

[corvairbob]

If you take your SIM card and your microSD card, and put them both next to each other you'll see that they're different as far as shape and dimension, and that the metal contacts differ in number and location. Now visualize your phone's card slot -- the corresponding metal contacts have to be located to be in the exact same location when you have the tray inserted. A SIM card isn't going to fit into the tray's microSD card spot, nor will any of the contacts line up correctly if you do manage to jam it into place. There is no magic way tor a phone to move its own internal components to different locations, the slot is soldered permanently to the logic board.
You need to get a dual-SIM phone order to do what you want, or a phone with dual eSIM support. It's not just a hardware issue either, when your phone doesn't support multiple SIMs, more than one SIM card isn't going to work anyway. If the installed firmware doesn't already include dual-SIM support, it's not an option.

yes i know that the sd cards are not the same as sim card are. so i took the tray and put it in the phone about where the firs sim sould set in the phone if it had 2 sims and it did not register so either there is not actual connections or the program just will not read that sim in that spot


so i think my best action will be to either to just get a tracfone card for the next few cycles and see if this free metro number goes ofline again and then just put the tracfone sim back into this phone. or to see if i can get a good dual sim phone the is 128gb for storage and then have both sims regitered to that phone. i can do the tracfone online but may have to call metro to get the metro sim connected to the new phone.
thanks