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

Hi,

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

@Uwe

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 NEX 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/591699/MacBook+is+killing+the+MagSafe+chargers
Take a look at comment #773
Also, this : https://www.ifixit.com/Answers/View/367629/Why+won't+my+controller+connect.
You can also check this video starting from minute 9:

The Vivo NEX 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 Vivo NEX 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 Vivo NEX 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 Vivo NEX 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://www.ifixit.com/Answers/View/630261/Microphone+doesn%E2%80%99t+work+on+voice+memos+and+Facebook+messenger

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

Reference: Have a board view or schematic (if available) to understand what components are under each shield and how they are attached. Component Not Detected: Camera, sensors, or other internal modules might stop being recognized by the system. Drops/Impacts: Severe physical trauma can jar screws loose or bend the frame, distorting screw holes. For cleaning, 99% Isopropyl Alcohol (IPA) is the go-to solvent, as it evaporates quickly and leaves no residue. Guaranteed Functionality (of the new part): Assuming you purchase a high-quality replacement part, you can expect the display to function perfectly, with accurate colors, brightness, and touch response. Tips for success include working slowly and methodically, keeping all screws organized (a magnetic mat is highly recommended), using the correct tools for each step, and always prioritizing ESD safety. Repairing a cracked polycarbonate back typically involves either a full replacement of the back panel (the most recommended and effective solution) or, for minor cracks, a cosmetic repair using fillers and adhesives. Cleaning: If only dirt or minor corrosion is present, clean the connector thoroughly with isopropyl alcohol and a fine brush. With the necessary internal components removed or shifted aside, you should now have clear access to the button flex cable. This is a very powerful but dangerous method, only to be attempted with extreme caution and the exact correct firmware files (often `.mbn` or `.xml` format). Check Charging Port Assembly: Disconnect the USB-C daughterboard's flex cable. The implications of incorrect screw handling extend far beyond a loose component or a rattling phone: Lead is a heavy metal known to be a potent neurotoxin, developmental toxicant, and environmental contaminant. When a phone is opened, these seals are broken, and their integrity is lost. The central component managing this complex power distribution is the Power Management Integrated Circuit (PMIC), often referred to as the PMU (Power Management Unit) or Charger IC (though a dedicated charging IC might also be present). Is it flush all around? Are there any visible gaps? Gently press around the perimeter to ensure it's securely seated. Look for bent or missing pins (on ZIF connectors) or damaged contact pads (on snap connectors). Soft Cloths or Microfiber Towels: To protect the phone's surfaces during the straightening process. The presence and severity of thermal discoloration directly correlate with the degree of heat damage. While software glitches can occasionally cause Wi-Fi issues, persistent problems often point to a hardware defect in the antenna, its connector, or the associated flex cable. Read recent reviews, especially negative ones, for clues about quality. New Adhesive Strips: If the original screen/back cover was glued and you need to re-seal the device, especially for water resistance. Damage during repair: Inspect other components, especially surrounding flex cables or the motherboard, for accidental nicks or bends. Look for Obvious Damage: Fractured components, bent pins, missing components, burn marks, discoloration, corrosion (especially around charging ports or areas of suspected liquid damage), lifted pads, or signs of previous repair attempts (poor solder joints, flux residue). If the problem is isolated to specific video apps (e.g., YouTube), their cached data might be corrupted. Once in Safe Mode, go to Smart Lock settings and check the Trusted Face functionality. The motor itself might be held into the mount by light adhesive, small clips, or simply seated by friction. Inspect the solder balls under the microscope for uniformity and proper adhesion. Always use the correct SIM ejector tool and handle the SIM card and tray gently. We'll start with the simplest, most common culprits, gradually moving towards more complex issues.

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