[SOLVED] I'm looking for LG Etna C330 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my LG Etna C330. 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.

@Kathryn

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 Etna C330 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/s22-ultra-chc-want-to-install-global-rom.4471847/
Take a look at comment #225
Also, this : https://xdaforums.com/t/external-storage-for-app.1968766/.
You can also check this video starting from minute 4:

The LG Etna C330 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 Etna C330 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 Etna C330 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 Etna C330 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/586203/Not+charging+-+restarting+when+plugged+in

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

This prevents short circuits and protects both the technician and the device. Any other small brackets, clips, or foam pieces: These are all part of the structural design. Bent/Deformed Metal Clips: If metal clips are integrated, they might be bent out of shape. The USB port on a smartphone is arguably its most heavily utilized physical interface. Diagnosing a short circuit is a challenging but rewarding skill in smartphone repair. In some designs, OVP functionality might be integrated into the PMIC itself or a Front-End charger IC. Always disconnect the battery immediately after gaining access to prevent any accidental short circuits. After any internal cleaning or component replacement, carefully reassemble the phone, ensuring all screws and brackets are replaced correctly, and reconnect the battery last. This could include metal shields, speaker assemblies, or even logic board connectors. Inspect the pads under the microscope for any damage, such as lifted traces or missing pads. A magnetic mat or small containers are helpful for keeping track of tiny screws, which often vary in size and length. Too Much Heat/Airflow: Can warp the PCB, damage nearby components, or blow away tiny passive components. Effectively evaluating and diagnosing ghost touch issues requires a systematic approach, distinguishing between software glitches and hardware malfunctions. 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. Document Everything: Take photos at every step, especially of screw locations and component placements. Data Privacy: Ensure any chosen solution complies with data protection regulations (e.g., GDPR, CCPA) if handling customer data. Multimeter (optional, for advanced diagnosis): To test continuity of the switch. Understanding the causes of bricking and the various unbricking procedures is crucial for any smartphone enthusiast, developer, or repair professional. Factory Reset (Wipe Data/Factory Reset): If wiping the cache doesn't resolve the issue, a factory reset is the next step. Debris/Corrosion: The headphone jack is a common point of failure for "headphone mode stuck" issues. Reballing a Ball Grid Array (BGA) chip is one of the most intricate and advanced micro-soldering techniques in smartphone repair. Use a heat gun or hair dryer on a low setting, moving it consistently around the edges of the screen/back cover to soften the adhesive. It might still be adhered to the display assembly itself, or it might be a completely separate part. Their primary role, much like thermal paste, is to bridge air gaps between heat-generating components and a heatsink or heat spreader. When a smartphone board has been subjected to liquid, even after meticulous cleaning and component replacement, residual vulnerabilities can remain. Description: These adhesives become tacky and flow when heated to a specific temperature and then form a strong bond upon cooling. Ensure all cutouts for screws, connectors, and other components match perfectly. Use a GPS Status & Toolbox App (Android Specific): Download a dedicated GPS diagnostic app from the Play Store, such as "GPS Status & Toolbox" or "GPS Test." These apps provide detailed information, including: Visual Inspection: Look for physical damage (frayed wires, bent prongs, scorch marks). When a smartphone is in EDL mode, its screen typically remains black, providing no visual indication of activity.

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