[SOLVED] I'm looking for LG G Pad III repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my LG G Pad III. 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.

@Leidy

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 G Pad III 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/806558/Why+is+my+internal+microphone+isn't+work
Take a look at comment #681
Also, this : https://www.ifixit.com/Answers/View/553706/Should+my+controller+power+on+without+the+LED-USB+ribbon+cable.
You can also check this video starting from minute 9:

The LG G Pad III 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 G Pad III 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 G Pad III 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 G Pad III 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/781475/Pokemon+X&Y+%22No+game+inserted%22

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

Reboot Device: A simple restart can often clear temporary software glitches that might be causing the flickering. Rule Out Battery Issues: A completely drained or faulty battery can mimic a hard brick. If external cleaning doesn't work, the issue likely lies deeper within the phone. Don't carry it in your back pocket where it can be bent or put under pressure when sitting. If neither software re-flashing nor button flex cable replacement solves the problem, it's highly likely a more severe motherboard issue (e.g., faulty storage, power management IC) or a deeply corrupted bootloader that can't be fixed by conventional flashing. Screen separation issues point to poor adhesive application or curing. Carefully open your smartphone, following a reliable teardown guide for your specific model. Antenna Issues: The antenna is responsible for sending and receiving Wi-Fi signals. Ensure all important photos, videos, documents, contacts, and any other irreplaceable data are safely backed up to a cloud service (like Google Drive, Google Photos, iCloud, or manufacturer-specific clouds) or transferred to a computer or external storage device. Audio still muffled: The foam might be too thick, or the microphone opening might still be partially blocked by residue or the foam itself. Surface Compatibility: Ensure the adhesive is compatible with the materials it's bonding (e.g., plastic, glass, metal) and won't cause damage or degradation. This is highly dependent on the device's firmware and whether it supports different NAND configurations. Improper Reassembly: If a phone has been opened previously, misplaced screws, trapped cables, or incorrect component seating can interfere with antenna performance. Solder Paste: Lead-free or leaded, depending on the original solder composition and technician preference. The current draw will significantly increase, often ranging from 300mA to 800mA or more, potentially with fluctuations as different modules become active. This is often the most effective way to pinpoint the exact location of a short. For example, if a charging IC was replaced, test charging speed, recognition by a computer, and battery percentage accuracy. Disconnect Battery: As soon as you gain internal access, disconnect the battery. Be very careful not to burn yourself, especially if you increase the current. Unique Pairing: During the manufacturing process, each fingerprint sensor module is uniquely paired with its device's Secure Enclave/TrustZone. It directly addresses the fundamental issue of lost connectivity, saving a logic board from being discarded. Blocked Vents/Impeded Airflow: Though phones don't have active fans, thick cases can trap heat, and blocked grilles (if any) can prevent passive heat dissipation. Cotton Swabs/Q-Tips: Useful for applying cleaner to small, intricate areas, but be mindful of leaving behind cotton fibers. First, there's the camera module itself, an encapsulated unit containing the lens, image sensor, and associated processing circuitry. Aluminum polishing compound (e.g., Flitz, Mothers Mag & Aluminum Polish) The symptoms are often severe, directly impacting the phone's ability to power on or maintain operation: Restart the phone, toggle Airplane Mode on and off, ensure the operating system is updated, and try resetting network settings (found in Settings > System > Reset options > Reset Wi-Fi, mobile & Bluetooth). This requires opening the device for visual inspection and potential component replacement. Differentiate Scratch Depth: These methods are only for minor, superficial scratches that you can barely feel with your fingernail. If you transferred the front camera and earpiece speaker, test their functionality as well.

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