[SOLVED] I'm looking for Huawei nova 9 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Huawei nova 9. 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.

@Sajid

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 Huawei nova 9 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/Guide/Apple+Airport+Extreme+Model+A1408+Logic+Board+Replacement/32083
Take a look at comment #791
Also, this : https://xdaforums.com/t/xap-guide-interop-unlock-for-wp8-all-capabilities.2435697/.
You can also check this video starting from minute 9:

The Huawei nova 9 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 Huawei nova 9 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 Huawei nova 9 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 Huawei nova 9 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://www.ifixit.com/Answers/View/844790/Overheating+phone+while+using+Application+and+charging

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

This requires advanced diagnostics (multimeter, oscilloscope, schematics, boardview) to identify the damaged trace. Doesn't Power On At All (Dead): No response to the power button, no charging indication, no sounds, no vibrations. Stress Marks: Look for discolored areas or stress marks on the green solder mask, which could indicate underlying fractures in the PCB. Precision Screwdrivers (Pentalobe, Phillips, Tri-point, Standoff): As required by your phone model. Anti-Static Bags: All sensitive electronic components, especially logic boards and ICs, should be stored in ESD-shielding bags (often metallic, silvery bags) which act as a Faraday cage, protecting contents from external static fields. Identify the Locking Tab: These connectors have a small, hinged locking tab, usually black or brown, that secures the flex cable. Quality Control: Helps track technician performance, identify common part failures, and refine repair processes. Repair Implication: Replacement units are significantly more expensive. Place the phone face down and then face up on a perfectly flat surface (e.g., a glass table). DIY: Suitable for software issues, minor hardware repairs (display, battery, charging port) that allow the device to boot. When the solder visibly reflows, a vacuum pick-up tool is used to gently lift the chip from the board. Do not scratch too deeply or too broadly, as this can damage the trace itself or neighboring traces. Once the solder melts (usually indicated by a slight shimmer or movement of the chip), gently nudge the chip with tweezers. If the issue is just the button cap, you might only need to replace that. Smartphone microphones are essential for nearly all forms of communication and interaction with your device, from making calls and sending voice messages to using voice assistants and recording videos. Reset Network Settings: Android typically has an option under Settings > System > Reset options (or similar) to "Reset Wi-Fi, mobile & Bluetooth." This clears all saved Wi-Fi networks, Bluetooth pairings, and cellular settings without deleting personal data. Does the tape make proper contact with designated grounding points? Many shielding tapes require a connection to the device's ground plane to shunt EMI away. Underfill Issues: Many BGA chips have a polymer "underfill" material injected beneath them to add mechanical strength to the solder joints. Start with a moderate temperature and move the heat source constantly to avoid overheating any single spot, especially near the battery, which can be sensitive to excessive heat. Flashing Incorrect Firmware (Unlocked Bootloader): If the bootloader is unlocked, trying to flash an incompatible or corrupt custom ROM/firmware is a common cause of boot loops or soft bricks. This innovative packaging and interconnection method for display driver integrated circuits (ICs) has played a pivotal role in enabling the sleek aesthetics and high-performance capabilities we've come to expect from our mobile devices. This protects the screen from direct contact and helps distribute pressure evenly. Visually inspect the flex cable for any signs of damage: tears, creases, corrosion, or bent pins on its connector. Clear Workspace: Ensure your work area is clean, well-lit, and on an ESD-safe mat. Camera Not Working: The camera app crashing, failing to launch, or showing a black screen, especially if it works intermittently or after reboots, can be firmware related. The dreaded "boot loop" is one of the most frustrating and unsettling issues an Android smartphone user can encounter. Wear and Tear: Like all flash memory, SD cards have a finite number of write/erase cycles. With patience and the right tools, most users can diagnose and fix this common issue, restoring their phone's full haptic functionality.## 8. Never exceed temperatures that would be uncomfortable to touch or risk damaging internal components, battery, or adhesives (e.g., screen adhesive, internal cable adhesives). A flickering smartphone display can be a frustrating problem, but with a systematic approach, it's often fixable.

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