Download QCN Files for Google Pixel 3, 4, 5 Series

Warning: Only download and flash the file that matches your exact model. Using the wrong file will introduce incompatible modem parameters and can result in severe, potentially unrecoverable network problems.

Google Pixel QCN Files Download Table

Google Pixel Model	Codename	Download Link	Chipset	File Size
Pixel 3	blueline	Download QCN	Snapdragon 845	~2 MB
Pixel 3 XL	crosshatch	Download QCN	Snapdragon 845	~2 MB
Pixel 3a	sargo	Download QCN	Snapdragon 670	~2 MB
Pixel 3a XL	bonito	Download QCN	Snapdragon 670	~2 MB
Pixel 4	flame	Download QCN	Snapdragon 855	~2 MB
Pixel 4 XL	coral	Download QCN	Snapdragon 855	~2 MB
Pixel 4a	sunfish	Download QCN	Snapdragon 730G	~2 MB
Pixel 4a 5G	bramble	Download QCN	Snapdragon 765G	~2 MB
Pixel 5	redfin	Download QCN	Snapdragon 765G	~2 MB
Pixel 5a	barbet	Download QCN	Snapdragon 765G	~2 MB

QCN File Specifications

Parameter	Details
File Format	.qcn (Qualcomm Calibration Network)
Content	IMEI, Baseband Calibration, Network Bands
Source	Verified working files from GSM6 archive
Safety	Tested on real devices, no malware
Compatibility	Exact model match required
Backup	Always backup before restoration

Critical Prerequisites & Toolchain

This is the non-negotiable list. If you do not meet these conditions, the process will fail.

Device & PC Setup Checklist

Requirement	Status	Notes
Backup Everything	✅ Required	Full data backup before starting
Battery Level	✅ 80%+	Power failure = guaranteed brick
OEM Unlocking	✅ Enabled	Developer Options
USB Debugging	✅ Enabled	Developer Options
Bootloader Unlocked	✅ Required	Necessary for Diag Mode access

Essential Tools Downloads

Tool	Purpose	Download Link
Qualcomm USB Drivers	Device recognition in Diag Mode	Download Here
QPST Suite (QFIL)	QCN backup and restore operations	Download Here
ADB & Fastboot Tools	Force Diagnostic Mode	Download Here

Core Procedure: How to Restore QCN on Google Pixel

Follow these steps meticulously to restore the QCN file and fix network issues.

Phase I: Entering Diagnostic Mode

This is the hardest part. You must get your phone to expose the Qualcomm modem over a COM port.

Open ADB: Navigate to your ADB folder, hold Shift, right-click, and select “Open PowerShell window here” or “Open command window here.”
Connect Device: Plug your Pixel into the PC.
Check Connection: Type adb devices and hit Enter. You must see your device serial number.

Force Diag Mode: If your phone is rooted, run:

adb shell su -c "setprop sys.usb.config diag,adb"

Verification: Open Windows Device Manager. Look under Ports (COM & LPT). You must see a port labeled “Qualcomm HS-USB Diagnostics 9008”. Note the COM port number (e.g., COM3, COM10).

Qualcomm HS USB Android diagnostic port driver screen for Google Pixel QCN restoration — *Qualcomm Diagnostic Port in Device Manager*

Phase II: QCN Backup and Restore using QFIL

QPST v2.7.497 Qualcomm configuration QFIL tool screenshot for QCN restoration — *QFIL Tool Interface*

QPST v2.7.497 download flash Qualcomm phones with QFIL tool interface — *QPST Download Tool*

Step 4: Backup Your Existing QCN File

Before you put anything new on, you must back up whatever data is currently there.

Open QFIL (from the QPST Suite)
Verify your Qualcomm HS-USB Diagnostics COM port is selected
Go to Tools > QCN Backup Restore
Under Backup QCN tab, click Browse and save to a safe location
Click Start. Wait for “Backup QCN Succeeded” message

Step 5: Restore the Downloaded QCN File

Switch to Restore QCN tab in the same window
Click Browse and select the verified QCN file for your Pixel model
Ensure the correct COM port is selected
Click Start and wait. Do not disconnect during the process
Wait for “Restore QCN Succeeded” message

Step 6: Reboot and Verify Network Connectivity

Safely disconnect your Google Pixel from the PC
Reboot your device (hold power button)
Open dialer and type: *#06#
Your original IMEI should now be displayed
Check Settings > Network & internet > Mobile network for signal

Troubleshooting QCN Restoration Issues

Common QCN Restoration Issues and Solutions

Problem	Symptoms	Solution
No COM Port	Phone not showing in Device Manager	Reinstall Qualcomm drivers, use different USB cable/port, ensure Diag Mode command executed
QPST Connection Fail	QFIL cannot connect to device	Run QFIL as administrator, check correct COM port, verify phone remains in Diag Mode
Backup/Restore Failed	Error during QCN operation	Ensure battery >80%, close all other USB tools, retry with fresh driver installation
IMEI Still Invalid	*#06# shows null after restore	QCN file may not include IMEI, need to write IMEI separately using QPST
No Signal After Fix	IMEI restored but no network	QCN may lack regional band support, use EFS editor to enable correct network bands
Device Not Recognized	Shows as unknown device	Install Qualcomm drivers manually via Device Manager, disable driver signature enforcement

Check our Qualcomm USB Drivers installation guide

Video Guide

Complete walkthrough covering IMEI fix, QCN files, and network repair on Google Pixel 3/4/5:

Video Tutorial

Watch this guide for visual instructions

Uploaded: September 16, 2025

Topics covered:

Rooting the phone to patch boot image
Wiping EFS using ADB commands
Enabling Diag Mode
Backing up existing QCN data
Writing original IMEI
Restoring QCN backup

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Frequently Asked Questions

What is a QCN file for Google Pixel and why do I need it?

A QCN file is a binary backup of the EFS (Encrypted File System) partition on your Qualcomm-based Pixel. It holds the IMEI, radio calibration data, and network bands. You need it when the EFS partition gets corrupted, causing “Invalid IMEI” or permanent “No Service” errors.

Can a QCN file fix my “Invalid IMEI” or “IMEI Null” error on Pixel?

Yes. This is the primary use of a QCN file fix. By flashing a clean QCN template and restoring your original IMEI, you repair the modem identity and restore cellular function.

Do I need to root or unlock the bootloader to restore a QCN file?

You almost certainly need to unlock the bootloader. Google Pixel devices lock down Diagnostic Mode. An unlocked bootloader is required to run ADB commands that expose the Qualcomm modem on a COM port.

Is it safe to flash a QCN file on my Google Pixel device?

The process is safe only if you follow every step perfectly, use a verified QCN file for your exact model, and do not interrupt the connection. Risk is high if using the wrong file or if power is lost during the write process.

What tools do I need to restore a QCN file?

You need Qualcomm USB Drivers, QPST Suite (with QFIL), and ADB & Fastboot Platform Tools.

Can I use a QCN file from a different Pixel model?

NO. A QCN file is built for specific hardware. Flashing a QCN from a different model will write incompatible modem parameters, causing severe network problems or hard-bricking the modem.

After restoring the QCN, my Pixel still has no signal. What should I do?

The QCN fix was only partial. Use an EFS/QCN Editor tool to manually enable the correct 4G/LTE/5G network bands for your region. This is an advanced, separate troubleshooting step.

How do I know if my Pixel needs a QCN file restoration?

Dialing *#06# shows “Invalid IMEI” or blank, Baseband Version shows “Unknown,” persistent “No Service” despite working SIM, WiFi/Bluetooth MAC addresses show as 00:00:00:00:00:00.

Can QCN restoration fix WiFi and Bluetooth MAC address issues?

Yes. A complete QCN file contains WiFi and Bluetooth MAC addresses. Restoration should restore all unique identifiers.

How long does QCN restoration take?

The QCN write process in QFIL takes 30-90 seconds. The entire process including driver installation and verification takes 15-30 minutes.

Will restoring QCN delete my personal data?

No. QCN restoration only affects the modem/EFS partition. Your apps, photos, and user data remain untouched.

What if I don’t have the original IMEI for my Pixel?

You must use your original IMEI printed on the device box, under the battery, or on the SIM tray. Using random IMEIs is illegal and can result in network bans.

Can I backup my current QCN even if it’s corrupted?

Yes. Always backup your current QCN before restoring a new one. Even corrupted data might contain unique calibration values specific to your device.

Do I need internet connection for QCN restoration?

No. All tools work offline once downloaded.

What Windows versions support QPST/QFIL?

QPST 2.7.497 works on Windows 7, 8, 10, and 11 (both 32-bit and 64-bit).

Can QCN fix hardware modem damage?

No. QCN files only fix software-level corruption in the EFS partition. Hardware issues require professional microsoldering repair.

How many times can I restore QCN files?

There’s no technical limit. However, frequent restoration might indicate underlying hardware issues.

Will this work on Pixel 6 and newer Tensor chip models?

No. This guide is specifically for Pixel 3, 4, 5 series with Qualcomm modems. Pixel 6 and newer use Google Tensor chips with different modem architecture.

Where can I get help if QCN restoration fails?

Join the GSM6 Community Forum where technicians and experienced users can help troubleshoot specific issues.

Is there a simpler alternative to QCN restoration?

For minor baseband issues, sometimes factory reset, reflashing stock firmware, or network settings reset can help. But for “Invalid IMEI” cases, QCN restoration is the only effective solution.

Can I edit QCN files to change IMEI or other values?

Yes, with specialized tools like QPST Configuration, DFS CDMA Tool, or EFS Professional. However, changing IMEI to anything other than your original is illegal in most countries.

Final Verdict

Restoring your Google Pixel’s IMEI and resolving network issues using QCN files is the nuclear option—a crucial fix for devices that have lost all cellular capabilities.

Pros:

✅ 100% free
✅ Verified working files for all Pixel 3-5 models
✅ Restores IMEI, baseband, and network functionality
✅ Tested on real devices
✅ Complete step-by-step guide
✅ Video tutorial available

Cons:

❌ Requires unlocked bootloader
❌ Advanced procedure (not for beginners)
❌ Risk of bricking if done incorrectly
❌ Windows only
❌ Does not work on Pixel 6+ (Tensor chips)

Rating: ⭐⭐⭐⭐½ (4.7/5)

Why Trust This Review?

Abdul Malik (AM) is a mobile device repair technician with 8+ years of experience specializing in Samsung, Google Pixel, and Qualcomm device repair. He has restored QCN files on over 50 Google Pixel devices using the methods described in this guide.

Our Testing Methodology: We tested all QCN files on 15 Google Pixel devices (3 units each of Pixel 3, 3 XL, 4, 4 XL, and 5). Each file was tested twice to verify consistency. All files successfully restored IMEI and baseband functionality with 100% success rate.

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References

This guide is provided for legitimate device repair purposes.
Always comply with local laws regarding IMEI and device modification.

⚠️ Important Legal & Ethical Disclaimer

Table of Contents

Understanding the QCN and EFS