[SOLVED] I'm looking for Realme Narzo 20 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Realme Narzo 20. It's started acting up, and I'm looking for a detailed service manual with boardviews and schematics to properly diagnose and repair it. I need to take precise voltage measurements around the board, so having the right documentation would be very helpful.

Thanks in advance for your help.

Selected Answer

I actually found that service manual on a tech Discord server a while back. A really helpful member there shared a direct link to their blog and I've saved it. I'm happy to pass it along here. Hopefully, these boardviews and schematics help you fix your phone, just like they got me through my repair. Looks like we have the same model.

@Vicky

Absolute legend! That's exactly the info I was searching for. This is going to save me so much time probing in the dark. Seriously, thanks a ton for sharing the link!

Hi there,

I also have the Realme Narzo 20 and just downloaded the manual you shared. I'm pretty new to board-level phone repair, and this is a bit intimidating with all the tiny test points and the schematics. Could you point me in the right direction on how to start troubleshooting this ? Any advice on the first few things I should check would be a massive help.

Thanks so much for your time

General advices: start by checking the voltage at the battery connector on the board. With a known-good battery connected, you should see a steady voltage between 3.7V and 4.2V. After that, a great next step is to check the main power management IC (PMIC) for shorts. Using your multimeter in diode mode, check for shorts on the large input capacitors surrounding the PMIC.

Here are a few useful references for troubleshooting your device:
https://www.ifixit.com/Answers/View/265905/My+Tablet+wont+Boot
Take a look at comment #1146
Also, this : https://xdaforums.com/t/epic-4g-w-joeykrims-root-what-works-what-doesnt.767964/.
You can also check this video starting from minute 1:

The Realme Narzo 20 service manual and boardviews from the link above were exactly what I've been searching for. I couldn't find a complete, free copy anywhere else. Seriously, thank you for sharing this you're a lifesaver!

Hi everyone, I'm working on a Realme Narzo 20 with a no power issue and need some guidance with my measurements.
I'm detecting 3.3V on the VREG_MAIN line (pin 1 of the PMIC), which looks good, but I'm getting 0V on the VDD_CPU line (pin 8) where the schematics indicate I should see about 0.9V.
Since this is a core voltage for the application processor, could this missing rail be why the device shows no signs of life?
What's the best procedure to diagnose this further? Should I check for shorts on the CPU rail first, or look at the PMIC's enable signals?
I've already verified the main 3.3V and 1.8V power rails are present and stable.

My Realme Narzo 20 was working perfectly until yesterday when it suddenly went completely dead. Now it won't respond to the power button, doesn't vibrate, and shows no signs of life even when connected to a charger. I'm worried there might be a serious issue.

I have a decent multimeter, a basic soldering iron, and a healthy dose of patience. While I've successfully replaced iPhone batteries and charging ports, this will be my first attempt at actual diagnosis. The sheer density of BGA chips and microscopic components is honestly a bit overwhelming.

I'm particularly curious about the alcohol trick I've seen online where you apply isopropyl to the board and look for evaporation hotspots to locate shorts. Is this actually a reliable method for beginners, or are there better approaches I should try first with just a multimeter?

I learned this lesson the hard way last month with mine, it was declared "dead" by two different shops. The phone showed absolutely no signs of life - no charging indicator, no vibration, nothing. Before diving into complex board work, I decided to try one more basic test: wireless charging.

To my complete surprise, it actually heated up on the charging pad! This single discovery completely changed my diagnostic path. It turned out the issue wasn't with the main board or processor, but with the notoriously fragile USB-C port that had failed completely. A $15 replacement part and some careful soldering brought it back to life.

The moral? Always exhaust every external testing method before opening the device. Test wireless charging if available, try different charging methods, and don't assume the worst case scenario. Sometimes the most "dead" devices have the simplest solutions hiding in plain sight.

I suspect my issue might be related to that cheap, third-party fast charger I used at the airport last week... Now the device gets extremely hot during charging, the screen flickers at low brightness, and sometimes it randomly shuts down at 30% battery. Could this have damaged the power management IC or battery calibration?

If your Realme Narzo 20 starts acting up, random reboots, fast battery drain, or connectivity issues, there are several diagnostic steps you can take before assuming the worst:

• Check your charging habits: Using poor-quality chargers or wireless pads can gradually damage your battery and charging circuit, leading to unpredictable behavior.
• Inspect the physical components: A slightly damaged charging port, worn battery, or even accumulated pocket lint can cause issues that seem like major hardware failures.
• Monitor temperature patterns: If your phone gets unusually hot during specific tasks (like camera use or gaming), it could point to a failing component rather than a software issue.
• Use diagnostic tools wisely: Ampere for battery health, phone diagnostic codes (*#0*# on many models), and a thermal camera can reveal problems without opening the device.
• Know when to stop: If you see liquid damage indicators tripped or smell burnt electronics, it's time to consult a professional before causing irreversible damage.

Also visit this link it may help : https://xdaforums.com/t/bypass-the-locktime-on-an-oppo-a53.4607289/

Here's what I discovered on forums and technical databases:

If external factors, software, and battery health are ruled out, the problem is likely internal hardware. Never bend, twist, or apply excessive force to the battery, as this can damage the internal cells. Check for Carrier Locks: Devices purchased from carriers are often "bootloader-locked" by the carrier, preventing unlocking. Desoldering: Using a hot air rework station, carefully and evenly heat the RF transceiver IC to the appropriate temperature (usually around 300-350°C, depending on solder type). Light Emission: When a finger is placed on the designated area of the display, the display panel itself (usually an OLED screen) emits a bright burst of light. Structural Integrity: They distribute stress and maintain the rigidity of the device, especially against bending or twisting forces. The data on the eMMC/UFS chip is encrypted, and the decryption keys are stored in components like the CPU (SoC) and/or Secure Enclave. ESD Precautions: Use an anti-static mat and wrist strap to prevent damage to sensitive components. Fairphone often color-codes screws or uses consistent types to simplify things. Angle the flathead screwdriver against the remaining edge of the screw head, trying to get it to bite. Flash Stock Firmware via Recovery (if accessible): Some devices, especially those with custom recovery like TWRP, allow flashing official stock firmware packages (usually in `.zip` format) directly from recovery mode. Risk of Damaging Surrounding Components: The hot air can inadvertently heat and damage adjacent components, especially heat-sensitive ones like microphones, plastic connectors, camera modules, or even the battery. Smartphone motherboard flex cables are the unsung heroes of internal connectivity, linking various peripheral components to the main logic board. Place one probe on the corresponding pin at the USB-A end and the other probe on the same pin at the USB-C/Lightning end. Recalibrate Sensors (if available): Some Android phones offer a sensor calibration option in settings (often in developer options or specific diagnostic menus). Restart the Device: A simple reboot can often resolve minor software glitches that might be affecting sensor readings or calibration. Application: Apply the tape over areas that appear to be causing or receiving interference. Applications might crash frequently, even system-level apps, or exhibit "App Not Responding" errors with increasing regularity. Beyond the monetary savings, DIY repair offers several other compelling rewards: Replacing a SIM card reader is a delicate process, but with the right tools, technique, and patience, it's a common and effective repair that can save a seemingly dead phone.7. This helps the phone better understand your unique voice characteristics. Before embarking on this delicate journey, it's crucial to understand the high level of complexity involved and to acknowledge that improper execution can lead to irreparable damage to the motherboard, essentially bricking the device. Proper Reassembly: During reassembly, ensure all components are placed correctly, no cables are pinched, and all screws are installed. This is a critical period where a power cut or accidental disconnection can brick the device. It then sends an electrical signal to the phone's processor, indicating the cover's status (open or closed). These components are often densely packed on the Printed Circuit Board (PCB) and surrounded by other minute, heat-sensitive components like resistors, capacitors, and various Integrated Circuits (ICs). Remove Shields/Brackets: The motor or its connector might be covered by a small metal shield or bracket secured by screws. This method is less invasive as it avoids de-soldering the chip, making it quicker if successful. If the flex cable is secured by screws, carefully remove them using your precision screwdrivers. While applying gentle, consistent upward pressure on the suction cup, carefully insert a thin plastic opening pick into the very thin seam between the screen and the frame, typically starting from the bottom edge.

@Luna, Not sure what you're trying to say but ok :)