Xiaomi Redmi 4 — One of the most popular budget smartphones 2016-2017 It's still in use today, but many users have trouble installing it. SIM-maps: where the slot is, how to open it, what size SIM is needed and why the phone does not see the network after installation. In this article, we will discuss all the nuances of the process, from tool preparation to mobile Internet activation.
Features of Redmi 4 (including modifications) 4X and 4A) — A hybrid slot that supports either two nano-SIMs or one nano-SIM + microSD. This means that when you use two SIM cards, you can't expand the memory with a memory card, and vice versa, and we'll detail how to avoid configuration errors and what to do if the smartphone doesn't recognize the SIM.
This article will be useful for both beginners and experienced users who want to refresh their knowledge. MIUI 12-14 If you have a different Redmi model (like Redmi). 5 note 4), The principles will be similar, but the location of the slot may differ.
What are they? SIM-The cards are suitable for Xiaomi Redmi 4
The first thing to know before installing is the size and type of SIM card.Redmi 4 It supports only nano-SIM (format) 4FF, 12.3 × 8.8 If you have an old-style SIM (mini-SIM or micro-SIM), you will have to cut or replace it in the operator’s cabin. Using adapters or homemade croppings can damage the slot or contacts.
It is also important to consider the communication standard:
- 📶 2G (GSM) — It is supported by all operators, but only provides calls and slow internet (EDGE).
- 📶 3G (UMTS/WCDMA) — frequency-operate 900/2100 MHz (both bands are used in Russia).
- 📶 4G (LTE) — Redmi 4 range-support B1/B3/B7/B38/B39/B40/B41. In Russia, active B3 (1800 MHz), B7 (2600 MHz and B20 (800 MHz), but the latter may not be caught in some regions.
If you plan to use two SIM cards, make sure that both support the required standards, for example, if one SIM is only for calls (2G), And the second one is for the Internet (4G), Distribute them correctly – we will talk about this in the next section.
⚠️ Note: Some operators (e.g, Tele2 virtual MVNO) They can also issue SIM cards that do not support 3G/4G redmi 4. Before buying, check the technical specifications of the provider.
Where is the SIM card slot in Redmi 4?
In Xiaomi Redmi 4, including 4X and 4A) The SIM card slot is located on the left end of the case, next to the volume buttons, and is designed as a small hole with a metal tray that is extracted using a special key (SIM-eject tool). If you do not have a branded tool, a clip or needle with a curved end will do.
Visually, the slot can be identified by the following signs:
- 🔍 Small circular hole with diameter ~1 mm.
- 🔍 There could be a sign next to it. SIM or SIM card icon (on some modifications).
- 🔍 The tray is slightly recessed in the body and does not protrude outwards.
If you can't find a slot, you might have a different model.
- 📱 Redmi 4 Prime – a slot on the left end.
- 📱 Redmi Note 4/4X — top-end.
- 📱 Redmi 4A — slot on the left end, but the tray is shorter (only for one nano-SIM) + microSD).
| Model | Slot location | Slot type | 4G support |
|---|---|---|---|
| Redmi 4 (standard) | Left end | Hybrid (2 nano-SIM or 1 nano-SIM + microSD) | Yes (B3/B7/B38/B39) |
| Redmi 4X | Left end | Hybrid | Yes (B1/B3/B7/B38/B40) |
| Redmi 4A | Left end | Normal (1 nano-SIM) + microSD) | Yes (B1/B3/B7/B38/B40) |
| Redmi Note 4 | Upper end | Hybrid | Yes (B1/B3/B5/B7/B8/B38/B40) |
⚠️ Warning: Don't confuse a SIM card slot with a microphone hole or a headphone jack. If pressed incorrectly, you can damage the internal components of your smartphone.
Step-by-step: how to insert a SIM card
Now, let's get to the process. You're going to need to:
- 🔑 SIM-eject tool (or paper clip).
- 📱 Nano-SIM (one or two, depending on the configuration).
- 🔋 Make sure your phone is turned off (recommended, but not necessarily).
Step 1. Turn off Redmi 4 (press and hold the power button, then select Turn off) This will prevent possible failures in SIM card recognition.
Step 2: Take a SIM-eject tool and gently insert it into the slot hole to the point, and a slight click should be heard, after which the tray will extend slightly from the case.
Step 3: Remove the tray completely. Notice its design:
- 🔄 If the tray has two slots, it supports two nano-SIMs.
- 🔄 If there is one slot but there is room for a microSD on the side, it is a hybrid slot (one sim) + memory-card).
Turn off the phone.|Prepare a nano-SIM of the right size|Check the type of slot (hybrid or not)|Use the original SIM-eject tool-->
Step 4: Place the SIM card(s) in the tray:
- 📱 For one SIM: insert it in the slot SIM1 (usually marked).
- 📱 For two sims: in SIM1 It is recommended to install the main sim (for the 4G), into SIM2 — Additional (for example, for calls).
- 📱 For the Simki. + microSD: SIM in SIM1, A memory card in a separate slot (if there is one).
Make sure the SIM card contacts look down and the bevelled angle matches the tray shape.Incorrect installation can damage the contacts.
Step 5. Carefully insert the tray back into the slot before the click. Make sure it sits flat and doesn't protrude from the housing.
Step 6: Turn on your phone and wait until the download is done. If the SIM card is recognized, the network indicator will appear in the status bar (📶). If not, go to the section “What to do if the phone does not see the SIM card».
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If the tray is not inserted to the end, do not apply force! check if the SIM cards are installed correctly and if there are no foreign objects in the slot.
How to set up a SIM card slot in MIUI
Once you have installed the SIM card, you need to activate it in the settings. → SIM-Here you will see a list of available SIM cards (if there are two) and the parameters for each of them:
Main settings:
- 🔄 Name. SIM-Cards: You can assign a unique name (e.g., "Worker" and "Personal»).
- 📞 Calls: Selecting a SIM for Outbound Default Calls.
- 🌐 Mobile Internet: Selecting a SIM for data transfer.
- 📶 Type of network: 2G/3G/4G (recommended 4G (preferably for maximum speed).
If you have two SIM cards, pay attention to the priority of the network:
- 📱 SIM1 usually 4G, SIM2 — only 2G/3G (depending on the region).
- 📱 It is better to use the Internet SIM1, so SIM2 may not support LTE.
Also in MIUI There's a double function. 4G (if supported by an operator, which allows both SIMs to work online 4G. To turn it on:
- Go to Settings. → SIM-maps and mobile networks → Double. 4G.
- Activate the switch.
- Reboot the phone.
⚠️ Note: If you activate the double 4G One of the SIM cards has stopped working, so check if your carrier supports this feature. For example, MegaFon and MTS support, and some virtual carriers do not.
What to do if Redmi 4 doesn’t see the SIM card
If after installing the SIM card, the phone does not recognize it, the reasons may be as follows:
| Problem. | Reason. | Decision |
|---|---|---|
| Symbol is undetermined | Incorrect installation | Remove the tray and reinstall the SIM card, making sure the contacts look down. |
| No network. | Simka's not activated. | Call the operator or check the balance (sometimes a top-up is required to activate). |
| Only 2G. | Inappropriate range 4G | In the network settings, select Only 3G or 4G. |
| Simka works, but there's no internet. | Not configured access points (APNs) | Request settings from the operator or enter them manually in Settings → Mobile network → Access points (APN). |
| The phone says "No service." | Slot or SIMKA is damaged. | Try another SIM card. If there's a problem, contact the service. |
If none of these methods helped, reset your network settings:
- Go to Settings → System and device → Resetting → Network settings Reset.
- Confirm the action.
- Reboot the phone.
Redmi 4 with older firmware MIUI 10 may not have automatic settings APN. In this case, you'll have to enter the parameters manually:
Name: MTS
APN: internet.mts.ru
User name: mts
Password: mts
Type of authentication: PAP or CHAP
APN Protocol: IPv4/IPv6How to check if the SIM card slot works?
Frequent errors when installing a SIM card
Even experienced users sometimes make mistakes that lead to network problems.
- ❌ Using a micro-SIM without an adapter: contacts do not match the nano-SIM connector, resulting in poor connectivity.
- ❌ Installing the SIM upside down: Contacts should be facing the back of the phone.
- ❌ Ignoring the hybrid slot: If you insert two SIMs and a microSD, one of the SIM cards won’t work.
- ❌ Using a damaged SIM card: cracks, scratches or chips on contacts can cause failures.
- ❌ Setting up APN for the inappropriate operator: for example, the parameters of Beeline are not suitable for MegaFon.
Another common problem is that two SIM cards conflict, and if both SIMs are from the same operator (like two MTS), there may be network login errors.
- 🔄 Try to change the SIM places (switch). SIM1 and SIM2).
- 🔄 Turn off one of the SIM cards in the settings on 10-15 minutes, then turn it back on.
- 🔄 Update the firmware to the latest version MIUI (Sometimes bugs are fixed in new versions).
If the problem persists after all the manipulations, check if your SIM card is virtual (for example, from Tinkoff Mobile or SberMobil), some virtual operators do not support hybrid slots.
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Before buying a second SIM card, check with the operator whether it supports work in hybrid slots (for example, Tele2 Or Yota may not work properly in the SIM2).
How to Remove a Redmi 4 SIM Card Without a Tool
If you don't have a SIM-eject tool, you can use the tools you can use, the main thing is not to damage the slot.
- 📎 Paperclip: untighten it so that the end is straight and thin (diameter not more than 0.8 mm).
- 🪡 Needle or pin: suitable if the end is not too sharp (so as not to scratch the body).
- 🔑 Watch Key: Some Metal Keys to Replace Batteries Are Sizeable.
- 📌 Toothpick: if it is sharpened and wrapped with foil for stiffness.
How to remove the tray without a tool:
- Take a paperclip and bend it so that the end is perpendicular to the base.
- Carefully insert into the slot hole and press until the click.
- If the tray does not come out, slightly swing the clip left-right (without excessive effort!).
- When the tray is slightly pushed out, tuck it with a nail or tweezers.
⚠️ Warning: Do not use a knife, scissors or other sharp objects - they may damage the slot's O-ring or contacts inside the phone.If the tray is jammed, contact the service center.
If the tray is stuck inside and is not retrieved, try the following:
- 🔋 Turn off the phone and shake it slightly (sometimes the tray moves from place).
- 🔋 Light a flashlight into the slot - it is possible that the SIM card is set curved and blocks the mechanism.
- 🔋 If nothing helps, don’t try to pull the tray out by force – it can break the mount.