[SOLVED] I'm looking for REDD R1200 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my REDD R1200. 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.

@Abdo

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 REDD R1200 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/q-call-time-logger.1148391/
Take a look at comment #806
Also, this : https://xdaforums.com/t/1591139/.
You can also check this video starting from minute 7:

The REDD R1200 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 REDD R1200 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 REDD R1200 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 REDD R1200 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://xdaforums.com/t/wm6-5-cemail-does-not-show-new-email.519909/

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

Never apply excessive force, especially when prying or disconnecting flex cables, as this can easily bend or tear delicate parts. Functions: Advanced flashing, FRP (Factory Reset Protection) bypass, network unlocking, IMEI repair (legal aspects vary by region), bootloader unlock, direct eMMC/NAND operations, advanced diagnostics. Start at an edge that seems less adhered or has a larger crack, but be mindful of flex cables often located near the charging port or on the side (e.g., fingerprint sensors). Heat Gun/Pad: For softening old adhesive during disassembly and sometimes for promoting adhesion of the new gasket. Creaking Noises: When gently pressing on different areas of the screen or back panel, listen for creaking, clicking, or crunching sounds. Unlocking typically requires specific steps, often involving manufacturer tools or developer options, and usually wipes all user data as a security precaution. Always prioritize caution and precision over force to protect your valuable device.## 5. Restoring your smartphone's original display color profile can significantly improve your overall user experience. Remove the Faulty Camera Module(s): Once all screws and connectors are removed, carefully lift and remove the old camera module(s). Reset Phone Settings: Sometimes a "Reset Network Settings" or "Reset System Settings" (without erasing data) can resolve underlying communication issues. Malware, though less common, can also target and damage these critical sectors. However, due to the incredibly small size of components (some pins are barely visible to the naked eye), the proximity of other delicate components, and the multi-layered nature of smartphone PCBs, microsoldering is a challenging discipline that requires rigorous training and practice. Manufacturers frequently release updates that include fixes for sensor calibration, display drivers, and brightness algorithms. If after a factory reset, the boot time remains excessively long compared to a new device of the same model, it strongly suggests a hardware problem, most likely with the internal storage. Distinguish genuine linear cracks from harmless glowing flux residue, cosmetic marks, or accumulated dirt that might also fluoresce. Carefully place the new antenna into its designated position, ensuring it aligns correctly. The closer you are, the more concentrated and intense the heat will be. Scratches, even microscopic ones, can diffuse light, create distracting flares, reduce sharpness, and lead to hazy or muted photos. Provide clear instructions on how to remove their Google/iCloud accounts. Few smartphone problems are as frustrating and disruptive as random restarts. When it malfunctions , becoming unresponsive, stuck, or intermittent , it renders the device difficult or impossible to control. Carefully position and press the new display assembly into the frame, ensuring perfect alignment. Corrosion creates unintended electrical paths, leading to constant current draw. Battery Life: Current maximum capacity as a percentage of design capacity. Disconnect Screen Components: Carefully disconnect the various flex cables connecting the screen assembly to the logic board (display cable, digitizer cable, front camera/sensor cable). Preheat: Place the logic board on the preheater and set it to a safe temperature (e.g., 100-150°C). Be sure to remove the microSD card safely before handing over the phone for repair. If it's a bare chip, you'll need to reball it using a BGA reballing stencil and solder paste/solder balls. However, any time a water-resistant phone is opened for repair , whether to replace a screen, battery, or charging port , its factory seals are compromised. Check your phone's display settings under "Developer Options" or "Display" for such an option.

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