[SOLVED] I'm looking for DIJITSU Smart A11S repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my DIJITSU Smart A11S. 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.

@Tamer

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 DIJITSU Smart A11S 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/793957/screen+case+seal+heat+pressure+advice
Take a look at comment #619
Also, this : https://www.ifixit.com/Answers/View/298967/cant+get+it+out+of+network+boot.
You can also check this video starting from minute 4:

The DIJITSU Smart A11S 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 DIJITSU Smart A11S 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 DIJITSU Smart A11S 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 DIJITSU Smart A11S 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/859462/Nikon+Coolpix+P950+LCD+Display+show+light+no+image,+viewfinder+works.

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

Without transferring these paired components, a new TrueDepth module, regardless of its origin, will only enable the front camera and proximity sensor functions, but Face ID will remain permanently disabled with the "Face ID is not available" error. Many smartphone manufacturers (e.g., Apple, Samsung, Google) have internal diagnostic tools used by authorized service centers. Clear Workspace: Ensure your work area is clean, well-lit, and organized. Ceramic-based: Good thermal conductivity, non-electrically conductive, and generally safe. Position the Screen: Gently lower the new screen assembly into the frame, aligning it perfectly with the edges and cutouts. A short to ground on a power rail is a strong indicator of a faulty component on that line. Similarly, if you try to pair with a Bluetooth speaker or headset that supports NFC tap-to-pair, the pairing will fail to initiate when the devices are brought close together. Factory Reset / Wipe Data: This is a drastic step that erases all user data, apps, and settings, returning the phone to its factory state. If everything functions correctly, power off the phone again and disconnect the battery for safety before proceeding with the final reassembly. Quality of Replacement Parts: The quality of aftermarket replacement displays can vary significantly. TVS Diodes (Transient Voltage Suppression Diodes): These diodes protect against overvoltage spikes, such as those caused by ESD or power surges. Research Your Model: Display removal and flex cable locations vary significantly. Backup Data (if possible): If the phone is partially functional, back up any accessible data. On older iPhones (e.g., iPhone 6/6S), replacing the Wi-Fi IC might be a relatively straightforward swap (remove old, solder new). Its most notable advantage is its low melting point, approximately 183°C (361°F) for the eutectic alloy. Loose Port: If the port feels loose, its solder joints to the mainboard might be failing, or the flex cable might be compromised. Connect Display: Connect the display flex cable to the newly repaired/replaced connector, ensuring it's properly seated and clicked into place. If it's about smooth rotational movement (jerky gaming, AR drift), it points more to the gyroscope. This is paramount for safety as a connected battery, even if the device is off, can still pose a short-circuit risk or slowly discharge, potentially leading to damage or swelling during long-term storage. Connector Seating: Ensure the cable's connector is fully and evenly seated in its ZIF (Zero Insertion Force) or other socket on the logic board or sub-board. This indicates the battery's internal fuel gauge is out of sync with its actual capacity. Using a plastic spudger, gently flip up any retaining clips (for ZIF connectors) or pry up the snap connector. Replacement Waterproofing Adhesive Gasket: If your phone is water-resistant and you open it. Trace Repair: If any traces on the logic board under the baseband chip are lifted or damaged (common with severe impact or botched repairs), they may need to be carefully jumpered with fine enamel wire. Firmware Issues: Examining specific partitions or flashing firmware, though this typically doesn't involve decryption of user data. This requires microsoldering expertise and specialized tools, typically a job for a professional repair shop. Segregation: Immediately separate faulty or returned parts from good inventory. If pads are damaged, jumper wires might be necessary, but this significantly increases risk and difficulty on a flex. If a short is found in Step 2, this method helps locate the culprit component. Hot Air Rework Station: For safely removing and installing surface-mounted components.

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