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

Hi,

I'm hoping you can help me out with my Blu Grand XL. 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.

@Flor

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 Blu Grand XL 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/theme-change-doesnt-take-complete-effect.396581/
Take a look at comment #1110
Also, this : https://www.ifixit.com/Guide/Dyson+DC28+Animal+Sole+Plate+Replacement/77820.
You can also check this video starting from minute 8:

The Blu Grand XL 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 Blu Grand XL 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 Blu Grand XL 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 Blu Grand XL 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/487150/My+battery+is+bloated.+Is+this+the+reason+why+my+screen+turned+black

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

Often, small components like side buttons (volume, power), antenna lines, or button flex cables are integrated into or attached to the bezel. Very Fine Gauge Enamel-Coated Copper Wire (Jumper Wire): Typically 0.01mm to 0.05mm (AWG 42-50). The IC is placed in the stencil, solder paste is applied and wiped across, and then the assembly is heated until the paste melts into perfect solder spheres. Manual): Under Mobile network settings, try toggling "Choose automatically" for network operators. Connecting: Once paired, devices can reconnect automatically or manually. Go outdoors to an area with an unobstructed view of the sky (away from tall buildings, dense trees, or heavy electrical interference). Press the putty firmly onto the earpiece mesh and then onto each speaker grill. Apply Cleaner: Liberally apply IPA or flux remover to the area where soldering was performed. Use a thermal camera or freeze spray to locate the heating component/short. Replacing the mute switch is not a repair for the faint of heart or the inexperienced. Close Phone: Carefully align and reattach the back cover or display assembly, pressing firmly around the edges to ensure a secure seal. Software Indicators: Frequent app crashes, ANRs, specific services consuming excessive resources, or errors pointing to drivers often suggest software issues. Consult a service manual or an online teardown guide for your specific phone model to accurately pinpoint the exact location and attachment method of the antenna window. Battery is Very Swollen and Stuck: If the battery is extremely swollen and difficult to remove, or if you fear puncturing it, it's best to take the entire phone (with the battery disconnected) to a professional repair shop that has experience with hazardous battery removals. Partially reassemble the phone (connecting display, battery, and antenna) and test the Bluetooth functionality. Solder Paste: For specific applications, especially re-balling or BGA work. Corrosion: Look for green, white, or black discoloration on the metal contacts or within the port, indicating liquid damage or oxidation. Using a plastic spudger, carefully disconnect the battery flex cable from the logic board. If your phone has multiple lenses (wide, ultrawide, telephoto), switch between them. Even "no-clean" flux residues, while often benign, are usually cleaned by professional technicians for several reasons: People you call complain about excessive background noise, even in quiet environments. Reduced efficiency due to misalignment means less power is transferred, slowing down the charging process. Pairing/Serialization (If Applicable): If the phone doesn't boot due to pairing issues, and you have the expertise and tools, you would then attempt to transfer serial numbers or swap paired components. Once fully reassembled, perform a final, comprehensive test of the camera and all other phone functions to confirm the repair was successful and no new issues were introduced. Although sometimes a simple cleaning of the jack can resolve this, persistent issues frequently trace back to the IC's logic for detecting audio accessories. The computer identifies the device, loads the appropriate drivers, and establishes a communication protocol. It might reach recovery mode or fastboot/download mode, but cannot boot the OS. Replace Associated Flex Cable: If the motor is part of a larger flex cable assembly (e.g., integrated with a charging port flex or power button flex), consider replacing the entire assembly if inspection suggests damage to the flex, and the motor replacement alone didn't resolve it. When this mechanism fails, perhaps due to a bent pin, a jammed spring, or physical damage, it can render your SIM card inaccessible, effectively turning your advanced communication device into a glorified Wi-Fi tablet. Clean Other Components: Use IPA and cotton swabs or a soft brush to clean any water-damaged flex cables, camera modules, speaker contacts, and other removed parts.

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