[SOLVED] I'm looking for HEDY H767 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my HEDY H767. 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.

@Hamed

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 HEDY H767 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-dark-theme-for-th3ory.1322441/
Take a look at comment #1714
Also, this : https://www.ifixit.com/Answers/View/355400/Cant+delete+photos+from+my+computer+I+tried+using+itunes.+no+luck.
You can also check this video starting from minute 1:

The HEDY H767 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 HEDY H767 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 HEDY H767 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 HEDY H767 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/390639/Battery+life+is+short

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

Hardware: Use a hidden diagnostic menu (e.g., #0# on Samsung) to perform a touchscreen test. Locate the Volume Button Flex Cable: Once inside, identify the flex cable assembly connected to the physical volume button. OS updates often include bug fixes for storage drivers and compatibility issues. Note: While Google backs up a lot, it doesn't back up everything (e.g., all app data might not be included, specific game saves might be missing if the app developer didn't implement Google Drive backup). Internal (after opening): Once the phone is safely opened and the battery disconnected: Gently press down on the camera module to ensure it is seated, and then reconnect its flex cable connector to the motherboard. Low-temp solder creates weak, brittle joints and can be prone to corrosion if left on the board. Prioritize Critical Data: Identify what data you absolutely cannot afford to lose: Remember to proceed cautiously, especially with advanced steps like factory resets, and always back up your data. Simply replacing the fuse without identifying and fixing the underlying cause will only lead to the new fuse blowing immediately, or worse, permanent damage to other ICs or the PCB itself. For hardware troubleshooting, the phone needs to be carefully disassembled. Lack of Diagnostic Tools/Schematics: For obscure or rare issues, if you lack the necessary diagnostic tools or access to schematics/boardview software for a particular model, you might be unable to properly identify the root cause. At the heart of a smartphone's power system lies a sophisticated battery management circuit. The adhesive that secures the display assembly to the phone's frame plays a vital role in maintaining the device's structural integrity, protecting internal components from environmental ingress, and ensuring the proper functionality of the touchscreen and sensors. Restoring is equivalent to a factory reset and full OS reinstallation. Avoid direct sunlight or strong colored lights, as these will heavily influence your perception of the screen's colors. If successful, reassemble the phone and perform full functional testing. Start from one corner and work your way around, gently pressing it into place with your fingers or a plastic tool to ensure good contact. Composition: Typically a fluoropolymer-based coating (similar to Teflon). Backlight bleed, or light leakage, occurs when the light from the display's backlight unit (usually an LED strip along an edge) escapes unevenly around the display's perimeter. Focus on connectors, under ICs (if accessible), and any areas with green or white residue. Hot Air Method (Preferred for ease of multi-pin soldering): Apply a tiny amount of flux to the pads. Consult a service manual or an online teardown guide (like those found on iFixit) for your specific phone model to accurately pinpoint its exact location and how its bracket is attached. Initial Scan: With the phone opened and battery disconnected, thoroughly inspect the motherboard under good lighting (and ideally, a microscope). Android: Go to `Settings > Apps & notifications > See all apps > [App Name] > Storage & cache > Clear cache` (and optionally `Clear storage`). Even with good adhesion, significant drops or impacts can cause the screen to separate, especially if the frame itself is bent or warped. If repeating, allow adequate drying time between coats (usually 15-30 minutes, or as per kit instructions). Repairing damaged traces, replacing tiny surface-mount components (SMD), or running jumper wires requires extreme precision, a steady hand, and the right tools. Power Off Device & Disassemble: Power off the phone, remove the SIM tray, and carefully open the device (often by heating the adhesive around the screen or back cover). If the distortion changes significantly or disappears, it might indicate a problem with that specific microphone or its noise cancellation functionality.

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