[SOLVED] I'm looking for Sony ericsson K700 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Sony ericsson K700. 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.

@Katia

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 Sony ericsson K700 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/Teardown/Apple+Watch+Teardown/40655
Take a look at comment #252
Also, this : https://www.ifixit.com/Answers/View/94632/Power+Mac+G4+(MDD)+(M8570)+not+turning+on.
You can also check this video starting from minute 2:

The Sony ericsson K700 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 Sony ericsson K700 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 Sony ericsson K700 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 Sony ericsson K700 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/holly-crap-5g-network-is-gonna-be-sick.2419346/

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

Unstable Internet Connection: A dropped or slow Wi-Fi/cellular connection during download can corrupt the update file. This is less practical for smartphones without disassembly, but the subjective listening test is key. This guide will walk you through the process, equipping you with the knowledge to restore your phone’s wireless charging capabilities. Accelerometer and other IMU issues, however, frequently point to motherboard-level component failure, necessitating highly specialized repair techniques or, for most users, professional service or device replacement. It's often too large for casual analysis but invaluable for deep dives or reporting to developers. This section provides invaluable insights into what's consuming your battery. Slow Data Speeds: Web pages load slowly, streaming buffers, or downloads take an excessive amount of time, despite showing a strong signal. Calibration: This involves adjusting the sensor's output to match a known standard or to compensate for minor physical variances. Voltage: Start with a very low voltage, typically between 1.0V to 4.2V (never exceed the rail's nominal voltage, usually battery voltage). Description: Often a specific type of FPC or a custom, high-density Board-to-Board connector optimized for high-speed data transmission. Check for Software Updates: An operating system update might resolve underlying bugs. The moisture sensor is often integrated into the charging port flex cable. Test the power button's functionality: turn the screen on/off, long-press for power options, test volume buttons if they share the same flex. Drivers (PC Side): On a Windows PC, open Device Manager and check for any "Unknown Device" or devices with yellow exclamation marks under "Universal Serial Bus controllers" or "Portable Devices." Update or reinstall drivers as necessary. Caution: Restoring a damaged EFS backup can further complicate issues. You will notice that at a specific angle, the display image becomes perfectly visible, bright, and correctly colored. Be extremely cautious around the camera area, wireless charging coil, and any flex cables that might be adhered to the back glass (e.g., NFC antenna). Replace Bottom Screws: Reinstall the two pentalobe screws at the bottom. For Fastboot, it involves a series of command-line instructions (e.g., `fastboot flash system system.img`). Take your time, work methodically, and refer to your guides constantly. The component causing the short will dissipate this energy as heat, becoming warmer than its surroundings. Update All Apps and OS: Ensure all your apps are updated to their latest versions, as developers frequently release optimizations and bug fixes. Sometimes, a zero-ohm resistor (marked "0" or "000") is used as a sacrificial link, essentially acting as a fuse. Disconnect Battery: Immediately disconnect the battery flex cable to prevent any accidental shorts. Symptoms of a dead or failing audio IC often include no audio whatsoever, or constant static/buzzing that persists even after software resets. Troubleshooting such an issue involves a systematic diagnostic process, moving from simple software checks to complex hardware inspections. This allows for targeted solutions, whether it's a simple software fix or a more involved hardware repair, ultimately saving time and preventing further issues. Once cool, meticulously inspect all solder joints under the microscope. This involves analyzing current draw from a DC power supply, thermal imaging, diode mode readings on associated components, and symptom analysis (e.g., iPhone "no touch" often points to touch IC, "no service" to baseband). Prioritize Quality Part: Always use the highest quality earpiece speaker available.

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