[SOLVED] I'm looking for LG LMG810EAW G8S ThinQ repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my LG LMG810EAW G8S ThinQ. 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.

@Santiago

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 LG LMG810EAW G8S ThinQ 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/Guide/iPhone+3GS+Logic+Board+Replacement/1543
Take a look at comment #155
Also, this : https://xdaforums.com/t/q-sola-problem-with-games-and-or-rooting.2523930/.
You can also check this video starting from minute 4:

The LG LMG810EAW G8S ThinQ 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 LG LMG810EAW G8S ThinQ 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 LG LMG810EAW G8S ThinQ 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 LG LMG810EAW G8S ThinQ 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/Guide/Tapwave+T2907US+Zodiac+2+Shoulder+Button+Replacement/8038

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

Higher temperatures risk damaging the battery, plastic frames, flex cables, and even the display itself. Begin with external checks like cleaning the lens and microphone ports, move to software troubleshooting like clearing cache and updating apps, and finally consider hardware implications like storage speed, processor load, or potential camera module failure. Avoid Overheating: Extreme heat can make plastic more brittle over time. Jumper wires are deployed in situations where the original copper trace is damaged beyond conventional repair methods (like simply scraping and re-tinning). By meticulously following these steps and adhering to the safety and precision guidelines, you can safely and effectively remove a broken charging port connector, setting the stage for a successful replacement and restoration of the smartphone's charging capability. Work slowly and methodically, avoiding brute force, which can easily damage delicate components. If the flex cable is secured by screws, carefully remove them using your precision screwdrivers. Take a mental note or even a photo, as you'll need to transfer them to the new tray in the same orientation. Verify the charging flex connector is properly seated on the motherboard. Test Points: Designated pads on the PCB (Printed Circuit Board) that allow technicians to measure voltages and continuity at various stages of the circuit for diagnostic purposes. Download and install the latest versions from your phone manufacturer's official website. Repeat this process several times, using a fresh piece of putty each time, until the mesh appears clear. Inspect the logic board area around the LCD connector and backlight components. This issue can stem from various causes, ranging from simple obstructions to intricate component failures requiring micro-soldering. Light Bleed: In a dark room, with the screen displaying a bright, uniform color (like white), observe the edges. Random Reboots: The phone restarts itself without warning (though this can also be hardware). Some motherboards might come pre-programmed with a generic IMEI that can be overwritten, while others might be entirely unassigned. Legal and Licensing Considerations: While generally permitted for personal devices, the intellectual property of OEM firmware, drivers, and associated software components can be complex. Neutralize: If possible, use plastic tools to gently cut the adhesive around the edges. Like volume buttons, the power button is typically integrated into a flex cable assembly that contains the tiny switch and its connection to the motherboard. Many charging issues stem from external accessories or software configurations. Surface Preparation is Key: Always clean both surfaces (the cable and the frame/component it's adhering to) thoroughly with 99% Isopropyl Alcohol (IPA) to remove oils, dust, and old adhesive residue. Using a flashlight, carefully inspect the charging port for any debris, lint, dust, or bent/corroded pins. Carefully work your way around the perimeter, separating the adhesive. Remove any dust, debris, or old adhesive residue using isopropyl alcohol and a lint-free cloth. Rogue Apps: Malicious or poorly optimized apps running excessively in the background. Visual Damage: Examine the headphone jack itself for any signs of physical damage beyond what was visible externally (e.g., internal cracks, corrosion). Cleaning Old Paste: Using a lint-free wipe or cotton swab lightly dampened with 99% isopropyl alcohol, gently wipe away all traces of the old thermal paste from both the top surface of the processor IC (or its heat spreader) and the corresponding contact area on the phone's frame or copper heat pipe. This typically involves removing the display and replacing the small earpiece speaker module, often integrated with the front camera or proximity sensor flex cable. Physical Damage: Visible cracks, bends, or broken pieces on the plastic tray itself.

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