[SOLVED] I'm looking for Bird S668 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Bird S668. 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.

@Marc

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 Bird S668 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/221314/I+dropped+my+cam,+now+the+pic+wont+focus!
Take a look at comment #1275
Also, this : https://xdaforums.com/t/hello-everyone.4683733/.
You can also check this video starting from minute 6:

The Bird S668 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 Bird S668 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 Bird S668 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 Bird S668 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/605028/Is+there+a+way+to+reglue+my+speaker

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

Many Android phones have hidden diagnostic menus (often accessed by dialing a specific code like `#0#` in the phone app, though codes vary by manufacturer). Disconnect the Display Assembly (Optional, but Recommended): For easier access to internal components, it's often best to fully detach the display assembly. Set your hot air rework station to the appropriate temperature and airflow settings for lead-free solder (typically 350-380°C with moderate airflow, but this varies by station and board). It comprises an array of tiny transistors and capacitors, acting as gate drivers and source drivers. Software Updates: Tools may need updates to support newer phone models or OS versions. Thoroughly clean the exposed camera lens(es) using a blower bulb and then a lint-free wipe with a tiny amount of IPA. Test Before Fully Reassembling: Once crucial components (like the screen and battery) are reconnected, it's often wise to power on the device and perform a quick functionality test before sealing everything back up. This powerful tool wipes the device clean, restoring it to its original out-of-the-box state, effectively giving it a fresh start. The vast majority of issues are resolved by cleaning lint from the port or replacing a faulty cable. Isopropyl Alcohol (IPA 99%): Excellent solvent for most adhesives and general cleaning. Battery Disconnection: Always disconnect the battery before making or breaking any connections on the logic board. Watch carefully as the solder melts and flows, connecting the port's pins to the board. They might have more advanced tools, like JTAG (Joint Test Action Group) or ISP (In-System Programming) boxes, that can communicate directly with the phone's eMMC/UFS storage to re-flash the bootloader or entire system, even on devices that appear completely dead. Provide them with the SIM card's ICCID (the long number printed on the SIM card itself) and your account details. The laminated nature means that often, a fault in any single layer necessitates replacing the entire display assembly (outer glass, digitizer, and LCD/OLED). This will format the partition, so ensure you have a flashable ROM ready afterward. Out-of-Circuit Measurement (Ideal but difficult): Desoldering the suspect capacitor and measuring its resistance out of circuit provides the most accurate assessment. For example, if you know your carrier uses Band 4 (fast) and Band 12 (coverage), and your phone is always stuck on Band 12 even in an urban area, it could indicate an issue with Band 4 support or antenna. Take a small piece of Blu Tack or similar sticky putty (e.g., poster tack). These tiny, often press-fit or ZIF (Zero Insertion Force) connectors are designed to be compact and efficient, allowing for the flexible routing of electrical signals in tight spaces. Corrupted Bootloader Partition: If you can still access Fastboot/Download/EDL mode, it might be possible to reflash the bootloader partition (or the entire stock firmware which includes the bootloader). Check Volume Settings: Ensure volume is turned up and silent mode is off. It can also damage the underlying surfaces, making it harder for new adhesive to bond correctly, compromising water resistance and structural integrity. While primarily for media playback, sometimes these can indirectly affect call audio. Open the Phone: Carefully disassemble the smartphone to access and remove the display assembly. Small, sealable, clear plastic containers or compartmentalized organizers will help keep parts sorted and protected from physical damage. Phone's bootloader might be locked and needs to be unlocked (some devices). Once in Fastboot mode, type `fastboot devices` in your Command Prompt/Terminal and press Enter. Function: Allow current to flow in one direction only, rectify power, protect circuits from voltage spikes. Donor Pin: Find a compatible donor connector (from a junk board of the same model or a new replacement connector) and carefully extract a single, intact pin.

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