[SOLVED] I'm looking for NINGBO BIRD S669 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my NINGBO BIRD S669. 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.

@Asia

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 NINGBO BIRD S669 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/nexus-6-un-uk-motorola-co-uk.2969986/
Take a look at comment #118
Also, this : https://xdaforums.com/t/gta-san-andreas-lagging-on-nice-device.3925919/.
You can also check this video starting from minute 5:

The NINGBO BIRD S669 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 NINGBO BIRD S669 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 NINGBO BIRD S669 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 NINGBO BIRD S669 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/InFocus+IN35W+Motherboard+Replacement/146174

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

Soldering Iron: High-quality, temperature-controlled, with a fine tip (e.g., chisel, knife, or small conical). Board Connectors: Ensure all connectors (especially for the charging port flex and battery) are securely seated and free of corrosion. Faulty Charging IC (PMIC): The Power Management Integrated Circuit on the mainboard is failing to regulate charging or power distribution correctly. Understanding the nuances of LCD and OLED technologies, meticulously transferring components, and performing thorough post-installation checks are all crucial for success. Once the adhesive is prepared, the reassembly of the display needs to be executed with equal care. Also, check for any dirt, dust, lint, or foreign debris lodged between the pins or within the connector housing. Remove any mid-frames or other components obstructing access to the RF shields. Over time, daily use inevitably leads to the accumulation of dust, lint, pocket fluff, and other debris in your smartphone's speakers, charging port, and headphone jack (if present). Protect Internal Side: Place the phone frame on a soft, protective surface. Learning to read schematics is a significant investment of time, but it transforms smartphone repair from a component swapping lottery into a precise, diagnostic science. Disconnect Module: Carefully disconnect the flex cable for that module. Separate Flex Cable Modules: Often, the antenna is a small module attached to a flexible printed circuit (FPC) cable that connects to the main logic board. This usually performs another data wipe and attempts to restore the device to its "locked" state. A clean surface ensures proper seating and contact for the new assembly. Replacing the LED flash module is a moderately complex repair, typically falling somewhere between a battery replacement and a logic board repair, as it often requires significant disassembly to access the component. Aesthetics: A visibly cracked or bent frame significantly detracts from the phone's appearance and resale value. This method requires opening the phone to push the old camera glass out from the inside. Also, ensure that your phone case isn't contributing to the problem by being ill-fitting or pressing against the button incorrectly. Use tweezers or a plastic spudger to gently pry it up, ensuring you don't damage other components or bend the flex cable excessively. This problem manifests as intermittent audio, crackling sounds, or even a complete lack of audio output through headphones, despite the phone registering that headphones are plugged in. Apply Flux: Apply a very thin, even layer of no-clean flux gel to the clean pads on the motherboard. The design of a smartphone logic board is a masterclass in compromise and optimization: Diode Mode Readings: With the charger disconnected and battery disconnected, set your multimeter to diode mode. It should fit snugly and securely over the flex cable connector, holding it down onto the logic board socket. Optimize Background: Change your phone's background to a plain, uniform color. A null IMEI means the phone isn't broadcasting this identifier, hence no network access. If the phone is extremely hot, exercise caution and avoid prolonged direct contact. This allowed for much thinner bezels, particularly on the top and sides. Test with Multiple Apps: To determine if the issue is app-specific or system-wide, test several different applications that rely on the barometer: It rarely completely removes a scratch but might make it less visible.

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