[SOLVED] I'm looking for Lenovo S930 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Lenovo S930. 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.

@Fabiana

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 Lenovo S930 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/think-tank-wp-7-on-the-vibrant.792798/
Take a look at comment #620
Also, this : https://xdaforums.com/t/compliment-the-person-above-you.1217250/.
You can also check this video starting from minute 9:

The Lenovo S930 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 Lenovo S930 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 Lenovo S930 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 Lenovo S930 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/480980/internet+interface+card,+what+is+the+max+download+speed

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

Excess Dye Removal: After a set penetration time, any excess dye on the surface of the motherboard is carefully cleaned away. If one of these deeply embedded components fails, or if the interposer connection itself is damaged (e.g., due to drops causing fractured solder balls), board separation becomes the only way to access and repair the fault. With patience and precision, you can restore your smartphone’s smart cover functionality and enjoy seamless operation once again. A smartphone that constantly overheats is more than just an annoyance; it can lead to degraded performance, rapid battery drain, premature component failure, and in severe cases, even pose a safety risk. Some smartphones have built-in diagnostic tools that can test hardware components, including microphones. Restart the Phone: A simple reboot can resolve temporary software glitches. Short: A reading close to 0mV (e.g., 0-50mV) indicates a direct short to ground on that line. Device Not Recognized: Try a different USB port, a different USB cable, or a different computer. Restoring apps from a backup: Attempting to restore a large number of apps simultaneously. This control is paramount for safely diagnosing and isolating faults without causing further damage, particularly during the initial boot sequence or when dealing with short circuits. If the flex cable is adhered to the frame, use minimal heat to soften the adhesive, making removal easier. Gently align and press the new camera's flex cable connector onto its socket on the motherboard until it clicks or feels securely seated. Locate the battery connector, which is typically a flex cable connected to the logic board. "Download mode" (or its equivalents like Fastboot mode for many Android devices, or Odin mode specifically for Samsung) is a special boot state on Android phones. Remove the case and clean around the buttons using a soft brush, a dry cotton swab, or a blast of compressed air (used sparingly and from a distance to avoid forcing debris further in). Most smartphone batteries are secured with strong adhesive strips or tabs. Before commencing any cosmetic repair, it's crucial to understand the type of finish on your smartphone's aluminum frame. Tap-to-Focus: Use tap-to-focus repeatedly on different areas of the scene. This prevents sound from playing through the internal speakers and can interfere with volume controls. Flux forms a protective barrier over the heated surfaces, preventing new oxidation from forming until the solder flows. While effective for video, especially in well-lit conditions, it can introduce artifacts (like the "jelly effect") and is less effective than OIS in very low light for stills, as it doesn't extend exposure times. The camera module connects to the main logic board via a flexible ribbon cable. Removable Backs: For some older smartphone models or those with easily removable battery covers, accessing the back is straightforward: simply pry off the back panel using a spudger or your fingernail. Monitor temperature using diagnostic apps (e.g., CPU-Z on Android, or specific iOS diagnostic tools). Professional Repair: If the wireless charging IC on the motherboard is suspected, this requires advanced micro-soldering and should be handled by a professional. Only perform this if other software fixes have failed and you are prepared to lose all data (unless you have a cloud backup). Software triage: Test for app conflicts (Safe Mode), ensure OS is updated, and consider a factory reset. Many phones have multiple microphones (e.g., for noise cancellation); ensure all are clean. The method varies by phone (often pressing and holding the Power button, then holding the "Power Off" option until "Reboot to Safe Mode" appears). Faulty PMIC or LDO: If input is good and output is bad with no shorts, the regulator itself is likely faulty.

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