Preparation: What to Know Before Installation SIM-POCO X3
Xiaomi Poco X3 (M2007J20CG and M2007J20CI) supports two nano-SIM cards or one nano-SIM + microSD card up to 512 GB. However, many users face problems when first installing: the tray is not pushed out, the SIM is not recognized or the phone requires a reboot. In this article, we will analyze all the nuances – from choosing the right card size to activating the mobile network.
Important: Poco X3 does not support eSIM — only physical nano-SIM (12.3 × 8.8 mm). If your old-style SIM (mini or micro), it will have to be cropped or replaced in the operator’s cabin. Also check if the card is activated: new SIMs often require registration through the site or a call to the hotline.
Where is the slot for SIM-card in Poco X3: photo and description
In the Xiaomi Poco X3, the SIM card tray is located on the left end of the case (when viewed from the front of the screen), easily identified by the small extractor clip opening (complete with the phone), above the slot, you usually see the SIM logo or two horizontal slots.
⚠️ Note: Do not confuse the SIM card slot with the headphone jack (3.5 mm), which is located on the upper end of the device. Also on the left side may be the Google Assistant button (depending on the regional firmware), but it is visually different - has a convex shape.
- 📍 The left side of the body is a slot for SIM-maps (under the tray lid).
- 🔍 Paper clip opening - diameter ~0.8 mm (do not use needles or toothpicks!).
- 📏 The size of the tray is standard for Xiaomi: 15 × 12 mm (suitable for nano-SIM) + microSD or two nano-SIMs).
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If you don't have a branded paper clip, use an unbended stationery or pin, the main thing is that the tip is flat and does not scratch the case.
Step-by-step: how to open the tray and insert SIM-map
The process of installing a SIM card in the Poco X3 takes no more than a minute, but requires care.
- Turn off the phone. This is not necessary, but it is recommended to avoid failures when recognizing the card. Press and hold the Power button → select Turn off.
- Find a clip hole on the left end and stick it all the way up. You should hear a slight click, which means that the tray is unlocked.
- Remove the tray with a neat motion (don't pull around the corner!) It has slots for two nano-SIMs or one nano-SIM + microSD.
- Install. SIM-map: 🔹 Contacts (the golden side) should be down. 🔹 Combine the beveled corner of the map with the beveled corner of the groove. 🔹 If you use two sims, the second is installed in the upper groove.
Put the tray back in.
Turn on the phone.
Phone's off.|Paperclip of suitable size|SIM-map is trimmed to nano-SIM|Contacts card clean (no dust/fat)|The tray is removed completely, without distortions-->
⚠️ Note: If the SIM is not determined after installation, check:
- 🔄 Correct orientation of the map (contacts down!).
- 🧹 Cleanliness of contacts on the tray (wipe with an alcohol napkin).
- 📶 Support your operator’s frequencies (e.g. Poco) X3 not working CDMA-Networks like Verizon in the US).
Frequent Mistakes and How to Avoid Them
Even experienced users sometimes make mistakes when installing a SIM card, and here are the most common problems and solutions:
| Problem. | Possible cause | Decision |
|---|---|---|
| The tray is not moving out. | The paperclip is too thin or the hole is contaminated | Use a thicker paperclip or clean the hole with compressed air |
| SIM-map not recognized | The card is not activated or inserted incorrectly | Check the orientation of the card, activate it from the operator |
| The phone only sees one SIM. | The second SIM does not support the current network (e.g. 5G) | Check the network settings in Settings → SIM-maps and mobile networks |
| There's a "No Service" error. | Problems with operator coverage or APN-knock-down | Restart your phone or reset your APN settings (see section below) |
The critical feature of Poco X3: If you use two of them SIM-The second card will not work in the second mode. 5G — The first one (Slot 1) is supported by 5G-It's a hardware constraint that you can't circumvent software.
What if the tray is jammed?
Network settings after installation SIM-map
Once a Xiaomi Poco X3 is installed successfully, it will normally automatically connect to the operator’s network, but in some cases, manual configuration is required:
- Operator Choice: Go to Settings → SIM-maps and mobile networks → Network Selection: Turn off Automatic Selection and select your operator manually.
- Setting up APN: Go to Settings. → SIM-maps and mobile networks → [Yours. SIM] → Access points (APN). Press Add Add Add. APN enter your operator’s parameters (you can find them on the official website).
4G/5G activation:
- In the same menu, select the preferred network type.
- For maximum speed, install 5G/4G/3G/2G (auto) (if your carrier supports 5G).
⚠️ Note: If after setting up APN The internet is not working, check it out:
- 🔒 Correctness of the data entered (especially the fields) APN, Username and password).
- 📵 Availability of coverage (check the network indicator in the status bar).
- 💰 Account balance (sometimes operators block the Internet with zero balance).
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If after all the manipulations the network does not appear, try to rearrange. SIM-card to another slot (if you use two SIMs), sometimes the first slot works more stable.
How to check if you have recognized SIM-map
To make sure that the phone correctly identified the SIM card, follow the following steps:
- Open Settings → About the phone → SIM-card status.
- Check status: 🟢 The network is available - it's okay. 🟡 No service - problems with coverage or settings. 🔴 SIM-card not found – card inserted incorrectly or defectively.
Try making a test call or sending an SMS to confirm your workability.
If the status shows IMSI unknown or registration error, this may mean:
- 🔄 Simka is blocked by the operator (for example, due to late payment).
- 🛠️ Damaged contacts on the tray or the card itself.
- 📱 Software failure (will help reset network settings in Settings) → System system → Resetting settings → Resetting Wi-Fi, Mobile Network and Bluetooth).
Additional tips: how to extend life SIM-card
To avoid problems with your SIM card in the future, follow these guidelines:
- 🧼 Clean the tray of dust and dirt regularly (use a dry soft brush or compressed air).
- 🚫 Do not remove the tray when the phone is turned on – this can cause the communication module to fail.
- 🔋 Avoid overheating – do not leave your phone in direct sunlight, especially if you use two sims (they heat up more strongly).
- 🔄 Periodically move the SIMs in places (if you use two) so that the contacts wear out evenly.
- 📱 Update the firmware - in new versions MIUI Often fix bugs with SIM card recognition.
If you travel frequently, consider using virtual numbers (like Google Voice or Airalo) instead of physical SIM cards, which will reduce the wear and tear of the slot and make it easier to change operators.
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If you plan to use the Poco X3 overseas, check your carrier’s frequency support. In the U.S., for example, the phone may not work with Verizon or Sprint networks due to a lack of CDMA support.