[SOLVED] I'm looking for Unknown Pop D1 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Unknown Pop D1. 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.

@Gloria

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 Unknown Pop D1 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/579315/What+are+my+CPU+upgrade+options
Take a look at comment #343
Also, this : https://www.ifixit.com/Answers/View/821793/Sering+restars+sendiri+diwaktu+tidak+digunakan.
You can also check this video starting from minute 7:

The Unknown Pop D1 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 Unknown Pop D1 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 Unknown Pop D1 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 Unknown Pop D1 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/Install+iJDMTOY+Front+Bumper+Tow+Hook+License+Plate+Adapter/36816

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

Suggest that customers change their complex personal passcode to a simple, temporary one (e.g., "1234" or "0000") before dropping off the device, and then change it back upon collection. Apple, for instance, has introduced a "Self Service Repair" program, offering parts and tools for some iPhone models (though often at a significant cost and still with part-pairing limitations). Button Combinations: Less common for this specific task, but some modes are entered via specific key presses during boot. Locate the battery flex cable connector on the logic board and carefully pry it up with a plastic spudger. Pad Reconstruction: If a component pad has been completely ripped off, leaving no copper for connection, more advanced techniques are needed. Use a plastic spudger to carefully disconnect the flex cable from its socket on the logic board. Target the Adhesive: Focus the heat directly on the area where the adhesive is located (e.g., the perimeter of the screen, under the battery, around the back cover). Heat the Device: Apply heat evenly to the edges of the display or back glass, depending on your phone's opening procedure. Sound is an integral part of the smartphone experience, from notification alerts and music playback to voice calls and video recording. For LCDs, it manages voltages for the liquid crystal layers and often for the backlight unit (though the backlight driver IC might be separate). Using Exacto Knife/Razor: If the mesh is heavily glued or damaged, you may need to carefully use the tip of an exacto knife or razor blade to scrape or pry away the mesh. Connectivity Problems (without physical damage): Wi-Fi, Bluetooth, or cellular data issues that aren't resolved by toggling airplane mode or rebooting. Android: Go to Settings > System > Reset options > Erase all data (factory reset). You'll likely need to remove some shields or a midframe to gain access. No Vibration: The phone does not vibrate for calls, notifications, or keyboard presses, even when settings are enabled. Mid-frame/Shield Removal: Remove any screws or plastic mid-frames/metal shields that cover the motherboard and the sensor module. It connects to the main logic board via a flexible ribbon cable (flex cable). Testing: Use a multimeter's diode test mode; should show a voltage drop in one direction and open in the other. Network Issues (for streaming): Slow or unstable internet can cause buffering that affects audio sync or quality for streamed videos. Plastic and metal spudgers: For prying open the device and disconnecting flex cables. Screen lift, where the display panel separates from the smartphone frame, is a common and frustrating issue in smartphone repair. Carefully open the phone according to its specific model's disassembly guide. Evenly heat the entire area around the connector, ensuring the heat is distributed to all pins and anchor points. By systematically eliminating potential causes, you can narrow down whether the issue is superficial, software-related, or indicative of a deeper hardware problem that may require professional intervention.### 1. Disconnect the Battery: Locate and disconnect the battery flex cable with a plastic spudger. Flashing Tool: This is software on your PC that handles the flashing process. Google Play Services is integral to many Android functionalities, including Smart Lock. Good Lighting: A desk lamp or flashlight is crucial for clear visibility. "Dual SIM Dual Active" (DSDA) phones are rare now but allow both SIMs to be fully active simultaneously. If you are replacing the display adhesive (recommended for water-resistant phones), apply new adhesive strips before seating the display.

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