[SOLVED] I'm looking for Huawei Honor 20E LTE-A repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Huawei Honor 20E LTE-A. 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.

@Tomasz

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 Honor 20E LTE-A 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/415781/Why+My+MacBook+Pro+turn+off+suddenly+when+I+running+high+cpu+needs+App
Take a look at comment #293
Also, this : https://xdaforums.com/t/how-much-could-i-get-for-a-evo3d-and-2-evo-shifts.1243866/.
You can also check this video starting from minute 7:

The Huawei Honor 20E LTE-A 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 Honor 20E LTE-A 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 Honor 20E LTE-A 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 Honor 20E LTE-A 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/q-apps-to-sd-card-mods-for-s3.2172722/

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

This raw battery voltage, often referred to as V_BATT or BATT_VCC, is then regulated and converted into various other voltages to power every component on the logic board. Align it perfectly over the clean camera lens and the designated area on the phone's housing. Dental picks, fiberglass scratch brushes, or very fine brass brushes can be used carefully under a microscope to physically scrape away stubborn corrosion. Speaker Coils: Measure the resistance across the two terminals of the earpiece and loudspeaker. Fine-tip Tweezers: For handling small components and pulling battery adhesive tabs. Gently insert a thin plastic spudger, opening pick, or plastic card (like a playing card) into the gap between the battery and the frame. USB-C Port Replacement: If pin misalignment is severe (e.g., broken pins, deeply bent pins that cannot be straightened) or if the port is physically loose or damaged internally, the entire USB-C charging port assembly will likely need replacement. This generally means the echo is originating from the other person's device or their network connection. Work in a clean, well-lit, and organized environment to prevent losing tiny screws or introducing dust. This helps determine if a recently installed app is causing the conflict. It’s distinct from a completely unresponsive screen (dead zone) or random, unintended touches (ghost touches) in that the inaccuracy is typically systematic and predictable. Clean Area: Clean any dust, debris, or old adhesive residue from the mounting area using isopropyl alcohol and a lint-free cloth. Standard smartphone repair kit (precision screwdrivers, plastic spudgers, opening picks, suction cup, heat gun/plate for screen removal). Look for any obvious signs of physical damage: burnt components, corrosion (especially from liquid damage), cracked ICs, or missing passive components like capacitors or resistors. Damaged Charging Port (Most Common): Physical damage (bent pins, debris creating a bridge) or corrosion from liquid exposure are the leading causes. Phase 1: Basic Checks (Eliminate the Obvious , Most Common Solutions) Boot Loop / Random Restarts: The phone gets stuck in a boot loop or restarts randomly. Component Damage: A physically damaged speaker (e.g., a torn cone, a coil issue) can alter its acoustic properties, effectively putting it out of phase relative to a healthy speaker, even if electrically connected correctly. It involves desoldering the actual NAND flash memory chip (the storage chip) from the motherboard. Near 0V / Short: A reading close to zero on a non-ground pin indicates a short circuit to ground. Remove SIM Tray: Always remove the SIM card tray to prevent it from obstructing the opening process. Be very gentle and avoid inserting tools too deeply to prevent damaging internal flex cables. Small screws, fragments of glass, or components can fly off during disassembly. Mishandling a connector can lead to irreparable damage, turning a simple component swap into a complex and costly motherboard repair. Gently press down firmly around the edges of the new lens to ensure the adhesive bonds securely. Insufficient Gold Removal: Not performing the "gold wash" thoroughly, leading to brittle joints. Some phones open from the back (e.g., many Android phones, newer iPhones), requiring removal of the rear glass or plastic panel. Capacitor Failure: Shorted capacitors can pull down the voltage or cause excessive current draw. Close Device: Carefully re-seal the device, ensuring the screen or back panel is properly seated and secured with adhesive. Secure and Cure: Use clamps specifically designed for phone repair or rubber bands to hold the panel securely in place for several hours (4-6 hours minimum, 24 hours ideal) to allow the adhesive to cure completely.

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