[SOLVED] I'm looking for LeEco Coolpad cool1 dual repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my LeEco Coolpad cool1 dual. 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.

@Don

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 LeEco Coolpad cool1 dual 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/did-i-break-it-touch-screen-issues.1450881/
Take a look at comment #1293
Also, this : https://www.ifixit.com/Answers/View/538136/I+want+to+change+my+iPhone+7+plus+body.
You can also check this video starting from minute 3:

The LeEco Coolpad cool1 dual 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 LeEco Coolpad cool1 dual 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 LeEco Coolpad cool1 dual 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 LeEco Coolpad cool1 dual 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/601791/Right+side+of+TV+going+dark.

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

You're looking for lint, dust, pocket fluff, food crumbs, or corrosion. This careful preparation is a hallmark of professional and responsible electronics repair, protecting both your device and your time investment. Under the microscope, carefully use a sharp blade or fiberglass pen to gently scrape away a tiny section of solder mask from both your chosen source and destination points. Modern smartphones are engineered with remarkable precision, featuring miniaturized components, delicate flex cables, and often strong adhesives. Update failures can stem from a variety of causes, ranging from simple user errors to more complex system file corruption or even hardware issues. Home Button / Touch ID Not Working: Damaged home button flex cable, not properly transferred, or non-original home button (for Touch ID). This serves several purposes: maintaining device security, preserving warranty terms, and ensuring a consistent user experience. Motherboard Issues: While less common, problems on the logic board can impact display function. Start with simple components and known good boards to get a feel for normal readings. Visual Inspection Under Microscope: Before applying any heat, use the microscope to thoroughly inspect the damaged charging port and its immediate surroundings. Anti-static Mat and Wrist Strap: To prevent electrostatic discharge (ESD) damage. Significant water or physical damage to the motherboard's modem chip or baseband circuitry is usually beyond DIY repair. Convenience: The very security features that protect your data in a secure folder are what make it difficult to restore after a major hardware change. Remove Residual Adhesive: Carefully scrape any remaining adhesive off the phone's frame using a plastic spudger or your fingernail. Schematics and Boardviews: Essential for understanding component locations, power rails, and troubleshooting paths. Sometimes, especially after impact, a motor can become dislodged from its mounting point. For repair work, solder wire and specialized low-temperature solder pastes are often used with hot air rework stations or soldering irons. Factory Reset: As a last resort for persistent software-based issues, a factory reset (after backing up all data) can eliminate deep software corruption that might be affecting the BMS. Inspect Charging Port: Visually inspect the charging port for any debris, lint, corrosion, or bent pins. Or, replacement of the front camera module that also includes these paired components. They protect the motor from impact and ensure its vibrations are efficiently transferred to the user's hand rather than dissipating within the phone's internal components. Very low light will naturally lead to noisier video, regardless of phone condition. Avoid pressing down aggressively, as this can introduce bubbles or force glue into unintended areas. Test the 5GHz connection from various locations within your home or office. However, the general steps to access the microSD card slot typically include: The entire assembly is suspended by incredibly fine springs or gimbals, allowing for precise, minute adjustments. Secure Connection: Ensure the flex connector is fully and securely seated on the logic board. Check that other functions, especially those related to components on the same flex cable (e.g., microphone, flash), are working. Connector Integrity (Motherboard Side): This is where a "loose connector" often refers to the connector itself being detached from the motherboard. Look for specific grounding screws or contact points that connect flex cables or the logic board to the frame.

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