[SOLVED] I'm looking for BLACKPHONE B3R repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my BLACKPHONE B3R. 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.

@Dave

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 BLACKPHONE B3R 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/Guide/Lenovo+Thinkpad+Tablet+1838+Button+Replacement/115600
Take a look at comment #1475
Also, this : https://www.ifixit.com/Guide/Samsung+Galaxy+A5+Back+Cover+Replacement/99648.
You can also check this video starting from minute 5:

The BLACKPHONE B3R 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 BLACKPHONE B3R 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 BLACKPHONE B3R 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 BLACKPHONE B3R 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/774989/My+Wii+will+not+turn+on.

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

Relevant Replacement Components: If you anticipate needing to replace a component, have the new one ready. Constant Throttling: The phone might constantly report high temperatures, leading to persistent performance throttling even when the device feels cool to the touch. In such cases, the digitizer or the entire display assembly might need replacement. Desoldering Braid/Wick: Copper braid impregnated with flux, used to absorb excess solder. While not as outwardly glamorous as the camera or as frequently discussed as the GPS, its function is surprisingly vital. Isopropyl Alcohol (IPA - 90% or higher) & Lint-free Swabs: For cleaning. Many Android phones have a hidden diagnostic menu where you can test individual components, including speakers. UV Curable Solder Mask / Adhesive: A liquid, light-sensitive polymer (often green, black, or red) used to insulate and secure jumper wires (e.g., Mechanic UV ink). Install New Mechanism: Carefully position the new SIM tray eject mechanism. Button Mechanism Repair: If the issue is purely mechanical, sometimes the physical button or the dome switch underneath can be repaired or replaced, though this is often integrated into the flex cable. Before attempting a CC IC replacement, it's crucial to rule out simpler causes: Factory Reset (If lines appear in screenshot, and all else fails): If the lines appear in screenshots and software troubleshooting hasn't helped, a factory reset is the last software option. This bracket is usually secured by one or more tiny Phillips head screws. Tools: Requires a stereo microscope, hot air rework station, fine-tip soldering iron, flux, desoldering wick, and a new, compatible Hall sensor IC. Bypass Passcode (if no other option): If you've forgotten your passcode and cannot unlock the device, reinstalling iOS (via restore) is the only way to regain access, but it will erase all data. Fixing a constantly overheating smartphone can range from a simple software adjustment to complex micro-soldering. Restore Backup: Restore your data from the backup you made earlier (contacts, photos, app data). On iOS, Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. Modern smartphones boast impressive levels of water and dust resistance, typically indicated by an IP (Ingress Protection) rating like IP67 or IP68. Apply Heat: Gently and evenly heat the edges of the phone where the adhesive is located. Many apps are available (e.g., "Screen Test," "Display Tester") that can display a full-screen solid color of white, black, red, green, and blue. Detecting "dust under display" issues involves careful visual inspection and differentiation from other screen anomalies. During the call, bring your hand or finger close to the top of the screen (where the earpiece is) and observe if the screen turns off. You can gently nudge it with tweezers to confirm it has reflowed correctly. If the tray is visibly damaged, stuck, or if the phone fails to detect the SIM only when using that specific tray, then replacement is the appropriate solution. Initial Test: Before fully sealing the phone, you can perform a quick test. Water, coffee, soda, or any other liquid can wreak havoc on sensitive electronic components, leading to a wide array of malfunctions, often delayed and unpredictable. Risk of Damaging Surrounding Components: The hot air can inadvertently heat and damage adjacent components, especially heat-sensitive ones like microphones, plastic connectors, camera modules, or even the battery. Display Color and Brightness Calibration: Adjusts the screen's color temperature, vibrancy, and brightness levels to look natural and function correctly (e.g., auto-brightness). Read recent reviews, especially negative ones, for clues about quality.

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