[SOLVED] I'm looking for LOGICOM E44 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my LOGICOM E44. 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.

@Jay

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 LOGICOM E44 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/250370/How+do+I+replace+the+headphone+jack
Take a look at comment #693
Also, this : https://xdaforums.com/t/morphgear-nes-style-landscape-skin.727602/.
You can also check this video starting from minute 9:

The LOGICOM E44 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 LOGICOM E44 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 LOGICOM E44 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 LOGICOM E44 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/538887/No+audio+out+of+rear+jack

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

Small, Soft Brush (e.g., anti-static brush, clean paintbrush): For cleaning delicate areas. Earpiece Speaker (Receiver): Located at the top of the phone, used for listening to calls when held to the ear. Then, turn your attention to the corresponding contact pads on the display flex cable. Some phones have a single flex cable that carries multiple signals, including Wi-Fi/Bluetooth, charging, or audio. If you suspect a short or a faulty IC, apply power to the logic board (connect a battery or lab power supply). Isopropyl Alcohol (IPA 90%+): For stubborn grime or light corrosion, used with a cotton swab or toothpick. Missing Connections: Could be due to damaged pads, insufficient solder, or poor reflow. Handle with Extreme Care: Lithium-ion batteries are powerful and can be dangerous if mishandled. If your phone opens from the back, apply heat evenly to the edges of the back panel for a few minutes using a heat gun or heating pad. The process for unlocking a bootloader varies significantly by manufacturer and device, but generally involves using fastboot commands on a computer. Desiccant Chamber: Placing the board in a desiccant chamber with silica gel packets can absorb moisture effectively. On Motherboard: Once the target trace or component pad is identified, scrape away a small section of solder mask to expose the copper. Component Failure: The backlight LEDs themselves can burn out, or more commonly, the backlight driver IC (Integrated Circuit) or associated passive components (coils, diodes) on the logic board fail. Recent SIM Swap/Upgrade: If you've recently upgraded your phone or performed a SIM swap, the new SIM might not be fully provisioned yet, or the old one might have been deactivated prematurely. If after trying software fixes and the gentle massage technique, the pixel remains stuck, it is highly likely a permanent hardware defect. Gyroscope drift refers to the phenomenon where the sensor's reported angular velocity gradually deviates from the true angular velocity, even when the device is perfectly still. Even with new adhesive, achieving a factory-grade seal is very difficult for a DIY repairer. Ensure all pads are perfectly clean, flat, and free of shorts or lifted areas. Use solder wick with a fine-tipped soldering iron to carefully clean and flatten the pads on the motherboard. Sometimes, it might show a charging animation but the battery percentage doesn't increase. Often, the ALS is integrated into a single flex cable assembly that also houses the proximity sensor (which turns off the screen during calls) and sometimes even the front-facing camera or earpiece speaker. The primary symptoms of a compromised UD sensor seal are inconsistent fingerprint recognition, frequent "fingerprint not recognized" errors, the sensor failing to activate, or the appearance of dust, lint, or air bubbles visible under the display where the sensor is located. Some penetrant systems use a "developer" powder or liquid that is applied after cleaning off the excess dye. "Ringings," excessive noise, or slow rise/fall times can indicate impedance mismatches, damaged traces, or faulty components (e.g., capacitors, pull-up/pull-down resistors). Safety: Prevent accidents, ensure proper ventilation, and protect against ESD (Electrostatic Discharge). Ventilation: If using flux or chemicals, ensure you're in a well-ventilated area. Hard Reset/Reboot: A simple restart can often clear temporary software glitches. Thin Metal Pry Tool (Optional): For creating the initial gap for screen separation, but use with extreme caution. The heat plate is a common, cost-effective, and generally fast method, but carries risks, especially for delicate OLED displays. It requires a commitment to transparency, informed consent, and technical excellence.

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