[SOLVED] I'm looking for LG Phoenix P505 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my LG Phoenix P505. 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.

@Patti

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 LG Phoenix P505 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/621025/Screen+displays+but+no+touch+capability
Take a look at comment #667
Also, this : https://xdaforums.com/t/question-new-icon.635132/.
You can also check this video starting from minute 8:

The LG Phoenix P505 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 LG Phoenix P505 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 LG Phoenix P505 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 LG Phoenix P505 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/755168/Pixel+3a+not+booting+after+fall.+Buttons+are+unresponsive.

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

Effectiveness on Strong Adhesives: Heat is highly effective at softening even the strongest, most resilient adhesives, including those used in many waterproof and premium devices. Gentle, Even Pressure: When finally seating the screen, apply gentle, even pressure across the entire display. Ensure every single trace and pad on both surfaces is perfectly matched. Carefully trim any excess wire as close as possible to the solder joints. Adhesive strips (for screen re-sealing): If your phone is water-resistant, new adhesive is crucial for maintaining that resistance. Always prioritize safety, especially when dealing with hot or swollen batteries, and remember that thorough diagnosis is the key to a successful and lasting repair.A smartphone's logic board is its brain, housing the CPU, memory, storage, and all the essential integrated circuits that make the device function. Specific App Malfunctions: Applications specifically designed to leverage barometric data (e.g., some drone control apps, specialized measurement tools) may fail to operate correctly or crash. Fuses are often overlooked but vital protective components in smartphone circuitry. Often, if dust is firmly lodged or the module's integrity is compromised, replacing the entire camera module is the safer and more reliable solution to ensure optimal image quality.Smartphones have become indispensable tools in our daily lives, and their performance hinges on many tiny, intricate components working in perfect harmony. They display real-time voltage (V), current (A or mA), and sometimes wattage (W) and accumulated charge (mAh). This wipes the device clean and reinstalls the OS, effectively eliminating all software corruption, excessive apps, and hidden processes. Gently remove and reinsert your SIM card to ensure it's properly seated. Schematic Diagrams and Boardview Software: Helpful for identifying touch-related pins on connectors and components. This is often achieved through ESD protection diodes (TVS diodes) connected between signal lines and ground. In the demanding world of smartphone repair, technical skill is paramount, but it must be tempered with a strong ethical compass. Coaxial Cable Connection: If your Bluetooth antenna uses a coaxial cable, meticulously inspect both ends. No Flux: Leads to cold solder joints, poor wetting, difficulty flowing solder, and potential damage from excessive heat application as you struggle to make the solder stick. Take your new, high-quality battery cell (without its own pre-attached BMS). Gently slide the new tray fully into the slot until it sits flush with the phone's frame. Plastic Spudgers and Opening Picks: For safe disassembly and disconnecting/reconnecting flex cables. Any specific symptoms, when the problem started, and what steps the customer has already taken. Using a very sharp scalpel or fiberglass pen, gently scrape away the protective solder mask (the green, black, or blue coating) from the copper trace on both sides of the break. Check Progress: After applying pressure for a few seconds, release and re-examine the frame. Open iTunes (Windows/older macOS) or Finder (macOS Catalina and newer): Keep Tips Clean and Tinned: Regularly clean your iron tip on a brass sponge or damp cellulose sponge and re-tin it with a thin layer of solder. Diagnosing Smartphone Issues Related to Overclocking or Custom Kernels Multimeter: For diagnostics, checking continuity, and verifying voltage. Short Circuits: A partial short circuit on the logic board, often caused by liquid damage or physical trauma, can draw excessive current. For example, open a web browser to a page with a prominent, static logo or a navigation bar that stays in place. For Fastboot, it involves a series of command-line instructions (e.g., `fastboot flash system system.img`).

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