[SOLVED] I'm looking for QQMEE Q115 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my QQMEE Q115. 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.

@Rosana

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 QQMEE Q115 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/app-ultimate-pro-for-star-pro.3092350/
Take a look at comment #1660
Also, this : https://xdaforums.com/t/do-i-have-to-give-it-up.3289290/.
You can also check this video starting from minute 7:

The QQMEE Q115 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 QQMEE Q115 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 QQMEE Q115 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 QQMEE Q115 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/free-hosting-for-ppc-developers.503031/

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

Fine-tipped tweezers: For handling tiny screws, connectors, and the sensor module. Static Discharge (ESD): Electrostatic discharge can damage the sensitive integrated circuits (ICs) on the display flex cable or the motherboard's display FPC. Restart the Device: A simple reboot can often clear temporary software glitches that might be interfering with sensor readings or brightness control. Component Mounting: Has screw posts and clips for securing the motherboard, battery, cameras, speakers, and other modules. Signal Integrity: Even minor damage can significantly degrade wireless signal strength. Before opening your phone, ensure you've tried basic external cleaning and software solutions: Its absence or malfunction significantly diminishes the user experience, leaving you without subtle alerts or satisfying tactile responses. In such cases, the frame itself might need replacement, which is a significant repair. Protection: It incorporates various protection circuits against overvoltage, overcurrent, and short circuits. It requires precision, expensive equipment, and a deep understanding of thermal profiles. Cut to Size: Using a sharp razor blade or Exacto knife on a clean cutting mat, cut a piece of new ACF tape slightly larger than the bonding area. Lens Inspection: Check the outer lens for scratches, smudges, or dust. It might be integrated with the front camera or earpiece speaker on a single flex. Custom ROMs/Rooting Issues: Flashing an incompatible custom ROM, kernel, or recovery, or a misstep during the rooting process, is a very common cause of boot loops for enthusiasts. Once you've located the antenna contact springs, carefully inspect them using good lighting and, if possible, a magnifying glass. Always prioritize safety and precision to avoid causing further damage to your device. Liquid Damage: Any liquid exposure can quickly corrode flex cables and connectors. Software/Drivers: The operating system and specific drivers interpret the touch input and translate it into actions. In this scenario, you're out the cost of the replacement screen, the tools, and potentially forced to buy a new phone anyway. Earpiece Speaker/Front Sensor Flex: In many designs, the secondary mic is part of the same flex cable as the earpiece speaker or front sensor array (proximity/ambient light sensors). Attempting a firmware reflash can also help differentiate between a software glitch and a persistent hardware communication issue. Once the old sensor is removed, clean the area thoroughly with isopropyl alcohol to remove any residual adhesive or dust, ensuring a pristine surface for the new sensor. If your phone is taking significantly longer to charge wirelessly than it should, even on a fast wireless charger, misalignment could be the culprit. If the logs show the system is trying to charge but the current is low or intermittent, it could be a hardware issue (port, cable, charging IC) or a software misinterpretation. 5GHz): If your router broadcasts both 2.4GHz and 5GHz networks with separate SSIDs, try connecting to the other frequency. Causes: Physical obstruction, worn-out switch(es), damaged flex cable, software glitch. If the battery is NOT swollen and you are comfortable, you might be able to use very gentle, indirect heat on the front side of the screen (away from the battery) to slightly warm the adhesive. Vetting Tips: Rely heavily on seller ratings, detailed product descriptions, and explicit statements about part grade. Safe Mode: Booting into Safe Mode (Android) or checking for app-related issues (iOS, by checking recent installs) can determine if a third-party app is interfering with audio processing. This is a non-negotiable safety step to prevent electrical shorts and damage to the device.

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