[SOLVED] I'm looking for IMI Messi 2 LTE repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my IMI Messi 2 LTE. 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.

@Dorota

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 IMI Messi 2 LTE 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/tablet-problems.3099285/
Take a look at comment #281
Also, this : https://www.ifixit.com/Guide/ROG+Strix+G15+G512LI+Disassembly/145093.
You can also check this video starting from minute 9:

The IMI Messi 2 LTE 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 IMI Messi 2 LTE 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 IMI Messi 2 LTE 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 IMI Messi 2 LTE 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/rooting-update.1397392/

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

Improper Installation: If the flex is not seated correctly or is pinched during reassembly, it can be damaged. Electronic Image Stabilization (EIS): This is a software-based technique. The depth and precision of laser etching are hard to replicate perfectly. Reconnect Components: If you fully removed the screen, now is the time to reconnect all flex cables (display, digitizer, etc.) to the motherboard. If hardware remains suspected after these steps, it's likely a hardware issue. If doing so, be extremely careful not to get any on the display area or camera/sensor holes. Damaged Antennas: Internal antennas (tiny components, often integrated into the frame or on flex cables) can be damaged by drops or water. Third-Party Repairs: If the screen has been replaced with a non-OEM (Original Equipment Manufacturer) part, or if the repair was not performed correctly, the new screen might have compatibility or quality issues resulting in poor calibration. Use a nozzle size that adequately covers the IC without excessive spread. Before panicking, it’s important to understand the different reasons why a phone might not turn on: Ensure it's not too loose (which could snag or break) or too taut (which could pull the solder joint). Look for signs of liquid damage, which is a primary culprit for grounding failures. Diagnosis: Measure the resistance of the thermistor using a multimeter. Flexible Form Factors: Can be made very thin and in various shapes, allowing for more efficient use of internal smartphone space. You will now see the old thermal paste, likely dried and crumbly, on both the SoC die and the mating surface of the heatsink. Workaround: Chip Transfer (Advanced Micro-Soldering): This is the only method for independent repair to potentially restore fingerprint functionality with a replacement physical button. Test touch functionality across the entire screen (drag an app icon around). Hot Air Rework Station Method: Once aligned, use the hot air station again. When hardware malfunctions, it typically generates errors, freezes, or abnormal behavior that is logged by the operating system. Wear gloves and eye protection, especially when using chemical flux removers. Screen Protector Kit (Optional but recommended): A fresh screen protector adds value. Carefully position the reballed or pre-balled new eMMC chip onto the pads, ensuring perfect alignment. Apps: Use temperature monitoring apps (e.g., CPU-Z, AIDA64 on Android; general system info apps) to track CPU and battery temperatures during high-load activities. Even After Factory Reset: Crucially, if performance issues persist even after a full factory reset (which wipes user data and reinstalls a fresh OS), it strongly indicates a hardware issue with the eMMC rather than a software problem or corrupted user data. A faulty PMIC can manifest a wide range of debilitating symptoms, from charging issues and rapid battery drain to a completely dead phone that won't power on. Understanding the intricacies of USB-C port repair is therefore crucial for maintaining the functionality of contemporary devices. Visual Inspection: Look at the battery for any signs of swelling, punctures, or physical damage. NEVER Force It: If the battery is severely stuck, swollen, and resistant to gentle methods, it might be safer to stop and seek professional assistance from a qualified technician. Over time, components can degrade, leading to slight shifts in color rendition, though this is less common with modern OLED panels. Plastic Spudgers and Opening Tools: Metal tools can easily short components or scratch PCBs.

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