[SOLVED] I'm looking for AUX V929 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my AUX V929. 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.

@Marcio

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 AUX V929 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/just-bought-a-mate-8.3526533/
Take a look at comment #205
Also, this : https://www.ifixit.com/Answers/View/324268/Why+won't+my+Samsung+S7+turn+on.
You can also check this video starting from minute 4:

The AUX V929 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 AUX V929 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 AUX V929 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 AUX V929 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-cant-find-filter-option.1163640/

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

Magnifying Lamp/Task Light: Even with a microscope, a flexible magnifying lamp with bright, flicker-free LED lighting is useful for general inspection and smaller component work. Unfortunately, internal storage chips are typically soldered directly to the motherboard, making replacement a complex and expensive procedure, often requiring specialized equipment and skills. Any repair or modification involving the phone's chassis or internal components must consider these antennas to avoid compromising crucial wireless performance.2. Test the specific wireless functionality (e.g., try connecting to Wi-Fi, making a cellular call, pairing a Bluetooth device). Fiberglass Scratch Brush (optional, for stubborn corrosion): Use with extreme caution and only on specific, robust contacts. Volume levels: Ensure the volume is turned up for the specific audio type (media, ringtone, call volume). Pros: Keeps screws securely in place, easy to visualize the original layout, can be wiped clean. Heat conducted from internal components is transferred to the frame, which then dissipates it to the ambient air through its outer surface. Handle Flex Cables Gently: These are very fragile; avoid bending, creasing, or pulling them. If, after all software troubleshooting and meticulous sensor testing, the accelerometer continues to exhibit erratic behavior or remains unresponsive in raw data readings, a hardware malfunction is highly probable. This effectively "clones" the cryptographic link, allowing the new sensor to function identically to the original. It manifests as phantom touches on the screen, where the device registers inputs that you aren't making. ESD-Safe Mat and Wrist Strap: To protect sensitive electronic components from static discharge. This tool is abrasive and can remove solder or damage delicate traces if misused. Pressure: Sitting on a phone, placing it in a tight pocket, or applying excessive pressure can cause bending or twisting. For some older Androids: The charging port might be directly soldered onto the main logic board, requiring advanced micro-soldering skills and specialized equipment. Thermal pads excel at filling larger, inconsistent gaps, or when there might be slight variations in component height. This involves carefully desoldering the baseband chip, cleaning the pads on both the chip and the logic board, reballing the chip with new solder balls using a BGA stencil, and then soldering it back onto the logic board. Test in Different Locations: Rule out local network congestion, dead zones, or Wi-Fi interference. Full Assembly and Testing: Reassemble the phone completely, install the battery, and perform a full functional test, including charging, screen operation, and all other features. Corrosion: As the liquid dries, it leaves behind residues (minerals, sugars, chemicals) that become electrolytes. Apply a generous amount of flux around the old touchscreen controller IC. Reballing: For BGA baseband ICs, if the issue is suspected to be cracked solder balls due to impact, reballing (removing the IC, cleaning old solder, applying new solder balls, and re-attaching) can sometimes fix the issue. It requires patience, meticulous attention to detail, and a steady hand. Clean the frame where the new glass will sit with IPA to remove all old adhesive. Do you hear any echo or unusual acoustic properties in your own recording? This tests the internal mic/speaker isolation without external network variables. Developer Options (Android): Provides access to CPU usage, running services, background process limits, and other performance monitoring tools. Performance Issues: Before a full panic, the phone might exhibit extreme lag, app crashes, or unexpected behavior. Thermal Camera (optional, but highly recommended for finding hot spots) There are two primary types of FPC connectors you'll encounter in smartphones:

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