[SOLVED] I'm looking for LG Optimus Me P350 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my LG Optimus Me P350. 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.

@Manolo

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 Optimus Me P350 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/q-acer-hdmi-special-settings.1431572/
Take a look at comment #542
Also, this : https://xdaforums.com/t/sensation-1-2-1-5ghz-core-clocks-manufacturing.1577294/.
You can also check this video starting from minute 6:

The LG Optimus Me P350 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 Optimus Me P350 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 Optimus Me P350 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 Optimus Me P350 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/739607/A11+Media+menu+is+stuck+in+screen

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

Broken Plastic Clips/Tabs: You might see small, snapped-off plastic pieces inside the phone after opening it, or feel rough edges on the mid-frame. Erratic current fluctuations can indicate an unstable power delivery from the IC. Testing with a Known Good Screen: This is often the most definitive diagnostic step for hardware issues. Magnification: For optimal clarity, use a magnifying glass, a jeweler's loupe (10x or greater is ideal), or even your other smartphone's camera with its zoom function enabled. Record yourself speaking normally, then play it back through the phone's earpiece and external speaker. Disconnect the battery flex cable immediately after opening the phone to prevent any accidental shorts. Games that utilize motion controls for steering, aiming, or character movement will become unresponsive or exhibit highly erratic behavior. Professional Hot Air Rework Station: With precise temperature control (±1°C), adjustable low airflow, and various nozzles. A heat gun or hair dryer will be required to soften adhesive securing the display or back cover. This is an advanced repair best attempted by those with prior experience in board-level component work. Compare to known good temperatures (typically below 45°C/113°F under normal operation). While the speaker driver itself is crucial, an often-overlooked yet equally vital component in achieving optimal sound is the speaker gasket. Professional Help: For deep scratches, cracks, or any concerns about DIY repair, always consult a professional phone repair service. Cleaning: Carefully clean the charging port with IPA and a non-conductive tool. The mid-frame, or housing, is the structural backbone of the smartphone, sitting between the screen and the logic board/back cover. Case: Remove any thick or metallic phone cases that might be blocking signals. If your phone has a non-removable battery, it's advisable to discharge it below 25% for safety. Test all functions: screen, touch, Wi-Fi, cellular signal, camera, charging, sound, etc. Isopropyl Alcohol (IPA) (90% or higher): Crucial for dissolving and cleaning old adhesive residue. If the problem continues on a freshly reset phone, it strongly indicates a hardware issue. Careful removal: If tape needs to be repositioned or replaced, carefully peel it off with ESD-safe tweezers or a spudger. Location: Always test the hotspot in a cool, well-ventilated area, away from direct sunlight or external heat sources. Replacing them, while a delicate task, is a common repair that can restore essential functionality to a smartphone. If you see the Apple logo or "Connect to Computer" screen, you've either held a button too long or not long enough. Visually inspect it for any signs of physical damage such as tears, bends, or corrosion. UV curing solder mask offers an elegant and robust solution for repairing these damaged traces, restoring the PCB's protective layer and ensuring long-term reliability. Major Power Consumers: Components like the CPU, GPU, NAND flash, display driver, RF transceivers, and backlight driver are significant power consumers and often have dedicated power rails derived from the main rail via the PMIC. Color balance aims to render true colors by correcting for the color cast introduced by different light sources. Unlocked Bootloader: A prerequisite for installing custom ROMs and kernels. Speakers: Inspect the earpiece speaker and any bottom-firing or stereo speakers for debris.

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