[SOLVED] I'm looking for Vivo iQOO U5x repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Vivo iQOO U5x. 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.

@Guy

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 Vivo iQOO U5x 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://xdaforums.com/t/q-what-modem-is-in-dutch-lse.2171511/
Take a look at comment #127
Also, this : https://xdaforums.com/t/lg-g-vista-vs880-laf-img.3191633/.
You can also check this video starting from minute 6:

The Vivo iQOO U5x 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 Vivo iQOO U5x 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 Vivo iQOO U5x 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 Vivo iQOO U5x 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/706629/Which+adapter+require+to+use+US+A+type+plug+in+Hongkong

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

Calibration Data Restoration: Restoring factory calibration data for sensors, cameras, or audio components. Analyzing these issues requires understanding the power delivery system and systematically identifying the component responsible for the excessive current draw. For experienced technicians, a multimeter can be used to check for continuity across the LED's terminals (if accessible and disconnected from the circuit) or to measure voltages at test points around the LED driver IC when the flashlight is commanded to turn on. Plastic Spudgers/Opening Picks: For safely prying components and disconnecting flex cables. Disconnect Battery: Locate the battery connector on the motherboard and use a plastic spudger to carefully pry it upwards, disconnecting the battery. Wireless charging operates on the principle of resonant inductive coupling. Identify Target Areas: Based on symptoms and visual inspection, identify components or areas likely to be causing or suffering from EMI. Cracks/Fractures: Use a magnifying glass or microscope to meticulously inspect the PCB for hairline cracks, especially around screw holes, near large ICs (CPU, RAM, storage), and around connectors. Fastboot Mode (various Android): Similar button combinations (e.g., Volume Down + Power). While it requires patience and a steady hand, it's a manageable task for an experienced DIYer or repair technician. Their operation is simple yet profoundly effective: a thin wire or filament within the fuse is engineered to melt and break the circuit when the current flowing through it exceeds a predetermined safe limit. Symptoms over Numbers: Even if software reports decent health, if you're experiencing severe battery drain, unexpected shutdowns (especially in cold weather or under load), or the phone only works when plugged in, a battery replacement is usually warranted. Power off the phone, apply heat to soften adhesive, and carefully open the phone. This often includes the earpiece speaker, front-facing camera, proximity/ambient light sensor array, and for iPhones, the home button/Touch ID or Face ID sensor. Before applying any external power (other than the multimeter's internal battery), you need to ensure no critical power rails are shorted to ground. Once the new shielding can is securely soldered and the mainboard has cooled, you can begin the reassembly process. Check Filters/Resistors: Use continuity or resistance mode to check tiny filters or series resistors in the GPS signal path or power lines. Boot into Recovery Mode: Power off the phone, then hold specific buttons (e.g., Power + Volume Down) to enter stock recovery mode. Torx (T2, T3, T4, T5, T6): Common in various Android phones, especially Samsung and Huawei. Remove Shields/Mid-frame Screws: Depending on your phone model, the Qi coil might be covered by a plastic shield or part of the mid-frame, secured by several small Phillips or other specialized screws. Understanding whether the issue is a manufacturing defect or a result of compromised seals helps in pursuing the appropriate resolution, which, in most cases, involves a full display assembly replacement to restore the screen's pristine visual clarity.5. These cables can become loose, torn, or corroded due to drops or liquid damage. This backs up content like images, videos, audio, documents, and even app data (for some apps) within the secure folder. If you removed a back cover or screen secured by adhesive, apply new adhesive for a secure seal. Always prioritize safety, especially disconnecting the battery, when opening the device. Adhesive Strips (Optional but Recommended): For resealing the device’s waterproofing and dust resistance. Navigate to the directory where your OTA update `.zip` file is stored. Test with a Known Good Battery: A dead or deeply discharged battery can mimic Charging IC symptoms. A short is like creating a sudden, easy shortcut directly from the high point to the low point, bypassing all the devices. Reconnect the Battery: Once all internal components are transferred and secured, reconnect the battery flex cable.

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