[SOLVED] I'm looking for Doogee U11 Pro repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Doogee U11 Pro. 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.

@Noe

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 Doogee U11 Pro 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/static-sound-coming-from-speakers-in-clash-of-clans.3805123/
Take a look at comment #1309
Also, this : https://www.ifixit.com/Answers/View/348764/Why+won't+my+nook+power+on+completely.
You can also check this video starting from minute 3:

The Doogee U11 Pro 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 Doogee U11 Pro 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 Doogee U11 Pro 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 Doogee U11 Pro 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/Wiki/Sony_VAIO_PCG-61611L_Troubleshooting

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

A smartphone's battery life is a critical aspect of user satisfaction, and a sudden, unexplained power drain is a clear indicator of an underlying issue. Inspect Traces: Under magnification, examine the solder pads and traces leading to the damaged connector. Install the New Front-Facing Camera Module: Take your new replacement camera part. By observing the compass's behavior in various environments and using sensor testing apps, you can differentiate between external interference, software glitches, and genuine hardware defects, ultimately leading to an effective solution for regaining reliable directional accuracy.6. If you see the Apple logo or "Connect to Computer" screen, you've missed the timing. They can help you identify if you're truly connecting to a 5G tower and the quality of that connection. Keep Microphone Ports Clean: Regularly use a soft brush to clear dust and debris from all microphone holes. Manufacturing defects, although rarer, can also result in inadequate adhesive application or improperly seated components from the factory. This is a crucial safety step to de-energize the mainboard and prevent any accidental short circuits while working with sensitive components. Identify Connection: Consult schematics or board views to understand which component or line the damaged pad connects to. A smartphone's display is its window to the digital world, and any form of discoloration can significantly degrade the user experience. For smartphone work, a typical digital storage oscilloscope (DSO) with a bandwidth of at least 100MHz is recommended, preferably with multiple channels to compare signals simultaneously. Software updates sometimes include sensor driver fixes or improved calibration algorithms. Damage to this small connector can manifest in a wide range of symptoms, from a phone that won't turn on to erratic charging behavior or random shutdowns. Apply heat: Use a heat gun or hairdryer to warm the edges of the screen or back glass for 1-2 minutes. Success hinges on precise temperature control, meticulous pad cleaning, accurate chip programming, and perfect alignment during soldering. Liquid Damage Areas: Pay extra attention to areas that show signs of water intrusion. Use a soft brush (e.g., a clean toothbrush) and cotton swabs to gently scrub away corrosion and liquid residue. If the sound persists, then the haptic engine itself is not the source of the buzz, but rather another loose component vibrating because the haptic engine is active. Note: Clearing data will reset camera settings to default, but won't delete photos/videos. Compass/Magnetometer: Rotate the phone in a figure-eight motion to recalibrate. Approximately 80% of charging issues can be resolved with these basic steps. Connect to TV/Monitor: If you get a display, you can then navigate the phone to back up data to a cloud service, external drive, or your computer. Transfer Components (if necessary): Some display assemblies come as "bare" units, meaning you might need to transfer components like the earpiece speaker, front camera, proximity sensor, ambient light sensor, or even the home button/fingerprint sensor from the old display to the new one. Official Software Tools: Utilize manufacturer-specific software (e.g., iTunes for Apple, Smart Switch for Samsung, Mi PC Suite for Xiaomi) to attempt a restore or update. Research your carrier's official APN settings online (a quick search for "\[Your Carrier] APN settings" will usually yield results) and compare them to what's on your phone. It will look like a thin slot with a small, pin-sized hole next to it. UV Lamp/Flashlight: A dedicated UV curing lamp (e.g., 365nm or 395nm wavelength) or a strong UV flashlight. Discoloration or a hazy appearance beneath the glass can also indicate adhesive degradation or water ingress into the adhesive layer. Thermal Management System: Many phones use thermal paste or pads between the CPU/GPU and a heat spreader (often part of the frame or a metal shield) to dissipate heat.

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