[SOLVED] I'm looking for Hisense HS-L681 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Hisense HS-L681. 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.

@Susanne

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 Hisense HS-L681 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/Guide/Pioneer+Steel+Wheels+Swivels+Replacement/17306
Take a look at comment #355
Also, this : https://xdaforums.com/t/theme-update-24-02-blue-greenglowhoneycomb-dialer-psd-files-for-themers.961856/.
You can also check this video starting from minute 3:

The Hisense HS-L681 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 Hisense HS-L681 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 Hisense HS-L681 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 Hisense HS-L681 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/moderator-contact-list.4048709/

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

While achieving a factory-new look can be challenging, a significant improvement is often possible, restoring your phone's aesthetic appeal and extending its lifespan.3. Carefully slide the pick around the perimeter, continually applying heat, until the rear glass can be lifted. Use Tweezers (with extreme caution): For very stubborn, thick deposits of corrosion that the brush can't remove, you can very gently scrape with the tip of a plastic spudger or the dull edge of fine-tip tweezers. This phase is about patience and strategic application of heat and solvent. Wire Routing: Confirm the jumper wire is securely routed, not under tension, and fully insulated. Check for App Permissions: Ensure the camera app has necessary permissions. Screen stays off after calls: Requiring you to press the power button to wake the screen. If you've meticulously followed all diagnostic steps, including a factory reset and thorough cleaning, and the poor audio during video playback persists, especially across all outputs, it's time to consider professional assistance. Specific Component Failure: A particular function might stop working, such as the camera, touch screen, or a charging port, because the traces leading to that component have delaminated. Anti-Static Mat and Wrist Strap (ESD protection): Crucial for internal work. PCB Traces and Vias: Look for severed traces, damaged vias (small holes connecting layers), or delamination of the PCB layers. Electrical Conductivity: Most thermal pads are electrically non-conductive, making them safer to use in crowded electronic environments where accidental contact with circuits is possible. If the mechanism is part of a flex cable or integrated into the SIM card reader, you might need to replace the entire reader assembly. Does it restart when plugged in, even at a seemingly high battery percentage? Another indicator of poor battery health. Many antennas are integrated into a plastic frame or a flex cable that wraps around the phone's perimeter. Secure New Flex Cable: Re-fasten any screws and ensure the flex cable lies flat. Several factors contribute to the degradation and eventual failure of micro-USB ports: Carefully disconnect all other flex cables attached to this assembly (e.g., front camera). For the best adhesion, use small clamps designed for phone repair, or wrap rubber bands tightly around the phone for 1-2 hours. Follow a model-specific guide meticulously, as this step is often the most challenging. Power Down and Disconnect Battery: Before commencing any disassembly, ensure the smartphone is completely powered off. Identifying an earpiece mesh obstruction is often a straightforward diagnostic task that can save users the hassle and expense of unnecessary repairs or component replacements. Prioritizing customer privacy through clear communication, explicit consent, strict access protocols, and robust staff training is not just good business practice, it is a fundamental ethical imperative. If the external display shows a perfectly stable image while the phone's screen continues to flicker, it strongly suggests that the issue lies with the phone's internal display panel or its direct connection, rather than the graphics processing unit (GPU) or the core logic board. Flex Cable Damage: The small flex cable connecting the trigger's switch to the logic board can be torn, pinched, or corroded. Apply heat to the edges of the display or back cover to soften the adhesive. As you remove each component, place it on your magnetic mat or in labeled containers in the order of removal. Limitation: Most smartphone resistors are too small for these markings. For Wi-Fi, this involves mechanisms like CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance), while Bluetooth employs a frequency hopping spread spectrum (FHSS) technique. Test another SIM in your phone: If another known working SIM card also fails to provision in your phone, it strongly suggests a problem with your phone's SIM card reader or internal software.

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