[SOLVED] I'm looking for SHIRU Hitomi 7 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my SHIRU Hitomi 7. 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.

@Andrea

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 SHIRU Hitomi 7 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-how-to-change-ugly-wifi-calling-icon-from-t-mobile.1751755/
Take a look at comment #1015
Also, this : https://www.ifixit.com/Wiki/Lenovo_ThinkPad_W540_Troubleshooting.
You can also check this video starting from minute 7:

The SHIRU Hitomi 7 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 SHIRU Hitomi 7 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 SHIRU Hitomi 7 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 SHIRU Hitomi 7 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/Guide/BLU+Energy+X+Plus+Battery+Replacement/56475

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

Its sole purpose is to manage all cellular communication , making calls, sending texts, and connecting to mobile data networks (2G, 3G, 4G LTE, 5G). Cracks: In the PCB itself (minor ones near edges might be fixable, major ones often mean board replacement). This shows all currently active background processes and their RAM usage. It requires advanced microsoldering skills, precise temperature control, and specialized programming knowledge. Discoloration: Flex cables or other plastic components may show discoloration (e.g., yellowing, darkening) due to liquid exposure. Internal Flex Cable Connection: Many charging ports are part of a flex cable assembly. Image Enhancement: Applies sharpening, contrast adjustments, and other optimizations. Gently pry out the battery (it's usually strongly adhered; isopropyl alcohol can help soften the adhesive underneath). A thorough inspection of smartphone frame clips, both externally and internally, is paramount. If the voltage is present but doesn't drop, the PMIC isn't receiving the signal, or the PMIC itself is faulty. Once the display assembly is carefully separated from the main housing, and the necessary shields or brackets covering the motherboard connectors are removed, the screen connector will become visible. Software-Related Considerations (Often impact EIS or general camera function): For soldered modules, patience, precision, and a steady hand are paramount. Do not pull the screen straight off; hinge it open like a book to avoid straining or tearing cables. Puncture: Puncturing a LiPo cell exposes its internal chemicals to oxygen, triggering a rapid chemical reaction that releases heat and gas. Digital Microscope/Jeweler's Loupe: For inspecting tiny components, solder joints, or corrosion in extreme detail. Flux promotes wetting and prevents oxidation during the rapid soldering process. Try a Different USB Cable: This is arguably the most common cause of USB issues. Gather Tools and Set Up Work Area: Ensure all safety equipment and tools are readily accessible in your well-ventilated, non-flammable workspace. Boots Directly to Recovery Mode: The phone bypasses the normal boot process and goes straight into the stock or custom recovery menu. Locate the Volume Button Flex Cable: Once inside, identify the flex cable assembly connected to the physical volume button. Set a low voltage (e.g., 3.8V for a phone) and a low current limit (e.g., 1A). Remove any components (e.g., mid-frame, logic board shields, other flex cables) that obstruct access to the motor. Desolder Original Chips: Using the hot air station and flux, carefully desolder and remove the identified chips from the original logic board. Carefully open the phone following a specific disassembly guide for your model. Test charging from a different power source (e.g., a computer's USB port, a power bank, a car charger). Carefully position the bent section of the frame between the padded jaws. Competence and Experience: Only undertake this service if the technician is highly experienced in flashing custom firmware for that specific device model and is proficient in recovery procedures. Remove Necessary Components: To reach the microphone flex cable, you may need to remove other components such as: Expected Result: If the logic board and PMIC are healthy, the phone should attempt to power on, vibrate, or show a charging animation (if connected to power).

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