[SOLVED] I'm looking for Allview V2 Viper S repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Allview V2 Viper S. 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.

@Hazel

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 Allview V2 Viper S 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/924536/The+coating+is+falling+off+of+my+driver+bits!
Take a look at comment #502
Also, this : https://xdaforums.com/t/q-god-awful-battery-life-on-latest-synergy-rom-release.2254867/.
You can also check this video starting from minute 8:

The Allview V2 Viper S 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 Allview V2 Viper S 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 Allview V2 Viper S 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 Allview V2 Viper S 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/call-issues-with-android-5-0.3107292/

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

Modern smartphone motherboards are incredibly dense, compact, and feature multiple internal layers where traces (electrical pathways) are routed. Careful Use of Metal Tools (Last Resort): If plastic tools aren't strong enough for very stubborn fragments: Physical Impact/Drops: Can damage the external button, bend the flex cable, dislodge the switch, or break solder joints. Hot Air Method (Preferred for ease of multi-pin soldering): Apply a tiny amount of flux to the pads. Constant plugging and unplugging of the charging cable, especially when done without care or by pulling on the cable rather than the connector, can bend or break the internal pins, loosen the connector's housing, or stress the solder joints. Applying uneven pressure or excessive force can easily crack the new screen during installation or the old one during removal. Pressing: Once aligned, gently press the new bump into place, applying even pressure around its edges to ensure the adhesive adheres properly. Low Speed is Key: Start with the absolute lowest speed setting on your rotary tool. Improper Reassembly: During a previous repair, if the motor wasn't properly re-adhered, screwed down, or if a gasket was lost/damaged, it will lead to mounting issues. For devices that support it, connect the smartphone to an external display (via USB-C to HDMI adapter, or wireless casting). If the new earpiece works: The original earpiece module was faulty and needs replacement. An ERM motor works by rapidly rotating an unbalanced weight (eccentric mass) around its central shaft. Water Damage: Water can cause corrosion on flex cable connectors or directly on the logic board, leading to an unresponsive digitizer. Less Risk of Damage: The design minimizes the risk of damaging flex cables or internal components during disassembly due to its open nature. Action: For Android, long-press the power button, then long-press "Power Off" (or similar) until a "Reboot to Safe Mode" option appears. Solder Paste: A mixture of tiny solder balls and flux, used for applying new solder to pads before placing an SMD. Inspect Frame: Check the phone's frame for any bending or damage that might have occurred during removal. EDL mode allows the PC to communicate directly with the phone's chipset, bypassing the corrupted bootloader. Sliding Technique: Once a small gap is created, slide the plastic opening tool along the perimeter, carefully slicing through the adhesive. Visual Inspection (Post-Disassembly): This issue is usually discovered during another repair or after opening a phone for troubleshooting. Back of Screen: Look for any foreign objects or irregularities on the back of the screen assembly itself that might be causing pressure. Identify Screw Type: Determine the screw head type and the exact nature of the damage. Analyzing background process drain begins with the built-in battery usage statistics, available in both Android and iOS. Tests to Run: Focus on "Sequential Read" and "Sequential Write" (important for large file transfers like videos) and "Random Read" and "Random Write" (critical for app loading, database access, and overall UI responsiveness). Microscopic Examination: Closer inspection of die markings on ICs, solder joints, or material finishes. Modulation/Demodulation: Converting digital data from the phone's CPU into analog radio signals for transmission and vice-versa. Physical Manipulation: Gently try to wiggle the buttons to ensure they're free. If the internal pins are bent or broken, this indicates damage to the SIM card reader itself, which is a much more complex repair requiring phone disassembly and potentially micro-soldering. Overtightening: Applying too much torque can strip the screw head or snap the shaft. It might be adhered directly to the back cover (if you fully removed it) or to the internal frame.

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