[SOLVED] I'm looking for Xiaomi Redmi K30 Racing repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Xiaomi Redmi K30 Racing. 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.

@Suresh

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 Xiaomi Redmi K30 Racing 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/647323/Sim+card+slow+to+detect+network+coverage
Take a look at comment #897
Also, this : https://xdaforums.com/t/q-att-galaxy-s2-lock-screen-when-watching-video-not-working.1302513/.
You can also check this video starting from minute 4:

The Xiaomi Redmi K30 Racing 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 Xiaomi Redmi K30 Racing 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 Xiaomi Redmi K30 Racing 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 Xiaomi Redmi K30 Racing 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/mi-note-5-pro-is-totally-dead.3834418/

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

Airtight Containers: Store parts in sealed plastic containers or airtight bags, especially in humid environments. For advanced hardware issues or devices with pairing restrictions, seeking professional repair may be the most prudent course of action.5. All solder balls should be uniform in size, perfectly spherical, and evenly spaced with no bridging (shorts) between them. Logic Board Repair (Advanced): If a new camera module does not resolve the intermittent focus, and the flex cable is confirmed good, the fault lies with the logic board. However, if multiple callers consistently sound muffled or quiet through the earpiece, an obstruction is highly probable. Repairing a cracked plastic back cover is a practical and satisfying DIY project. Divide the data into overlapping intervals of increasing length (`τ`, the averaging time). Dark Brown or Black (Scorched): This indicates severe, sustained, or very intense heat. Do not twist or pull at an angle, as this can damage the connector on the motherboard. Before even considering disassembly, a thorough external inspection can reveal significant clues about the extent and nature of the water damage. Detecting backlight bleeding effectively requires a systematic approach, a keen eye, and the right conditions. Value: For older devices, the cost of a complex baseband repair might exceed the device's value. Install the logic board, ensuring all connectors are accessible for later connection. If the "Update" option doesn't resolve the issue, or if you need a truly fresh OS install, you'll need to use the "Restore iPhone..." button. This seemingly mundane task, involving the thorough cleaning and inspection of the device's housing, is the silent hero that underpins the quality, longevity, and aesthetics of almost every repair, especially those involving display or back cover adhesion. Improper Repair: Accidental shorting during component replacement or incorrect component installation. USB Cable: A high-quality, reliable USB cable is essential for a stable connection. The human eye is remarkably adept at detecting color inconsistencies, but it can also be fooled by adaptation and ambient lighting. However, any attempt to alter an IMEI to circumvent blacklists, facilitate the use of stolen property, or obscure a device's true identity is illegal in most jurisdictions and carries significant criminal penalties. Clear Cache Partition (Android): In some cases, corrupt system cache data can lead to various anomalies. Enable Developer Options: Go to "Settings" -> "About phone" and tap on the "Build number" seven times until developer options are enabled. It requires precision and, in some cases, creative solutions or specialized techniques. It involves desoldering the old BGA (Ball Grid Array) chip and carefully soldering a new one onto the logic board. Mainboard Inspection (Advanced): If even a new display doesn't resolve the issue, the problem could be with the mainboard itself, specifically the touch controller IC (Integrated Circuit) or its surrounding components. Power Management IC (PMIC) Issues: The PMIC regulates power delivery to all components, including the Wi-Fi module. Visually inspect the flex cable for any signs of damage: tears, creases, corrosion, or bent pins on its connector. Identifying smartphone USB-pin oxidation is a crucial diagnostic step when troubleshooting charging, data transfer, or accessory connection issues. Verify the new sensor is the correct type and resistance value (if it's a thermistor). It acts as a shield against warping and delamination, protects delicate components from thermal shock and overheating, improves solder reflow consistency, and ultimately enhances the overall efficiency and safety of the repair process. Hardware Failure (Modem or Antenna): If none of the software or SIM-related diagnostics resolve the issue, and especially if the problem persists after a factory reset, it’s possible that there’s a hardware fault within your phone.

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