[SOLVED] I'm looking for Lenovo Z5 128GB repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Lenovo Z5 128GB. 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.

@Jessie

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 Z5 128GB 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/210406/Is+my+MacBook+Pro+dead
Take a look at comment #421
Also, this : https://www.ifixit.com/Answers/View/498601/Replace+amoled+with+no+loss+of+water+resitance+(glue).
You can also check this video starting from minute 6:

The Lenovo Z5 128GB 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 Z5 128GB 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 Z5 128GB 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 Z5 128GB 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/Guide/Acer+Aspire+5542G+keyboard+top+case+Replacement/25900

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

The display is arguably the most crucial component of a smartphone, serving as our primary interface with the digital world. Place the red probe on a known good ground, and touch the black probe to the various pins of the Charging IC (especially power, ground, and data lines) and surrounding capacitors. In modern smartphones, internal antennas are critical for almost all wireless communication, including cellular, Wi-Fi, Bluetooth, and GPS. This often means removing the back cover, battery, and then carefully separating the display assembly from the frame. Position the motherboard on the preheater and set it to a temperature around 100-120°C. The NAND flash memory Integrated Circuit (IC) is the solid-state "hard drive" of a smartphone. While not as robust for authenticity, many apps can provide battery health and detailed statistics. If you have a specific pre-cut replacement, simply peel off its backing. Modern smartphones incorporate sophisticated noise-canceling technology to enhance call quality, voice recording, and even digital assistant performance. The greatest risks are damaging internal components during removal, leaving shards that compromise the new adhesive, or failing to properly clean the frame. The phone's operating system misinterprets a signal, believing that a jack is inserted, and consequently routes all audio through a non-existent accessory. Understanding the root causes and applying a systematic troubleshooting approach is key to diagnosing and resolving this pervasive issue. Power Off Phone: Always ensure your phone is completely powered off before starting any repair. True hardware RAM testing on a smartphone typically requires specialized equipment (like JTAG programmers, BGA rework stations for chip replacement, or manufacturer-level diagnostic software) and is beyond what a consumer can perform. Evaluating these dual-SIM conflicts requires a structured troubleshooting methodology to pinpoint whether the problem lies with the SIM cards, network configuration, device software, or even hardware limitations. An unlocked bootloader, by contrast, allows the user to flash any compatible software onto the device's partitions, including unsigned or unofficial firmware components. Liquid Damage Residue: Dried liquid and corrosion products can sometimes break off and become loose fragments. Gentle Removal: As the solder melts (it will become shiny and liquid), gently nudge the component with fine-tipped tweezers. Flux Pen or Paste (if soldered): To facilitate solder flow and ensure clean connections. If opening from the back: Heat the back cover edges (if adhered), use a suction cup and pry tools to carefully separate it. If the issue persists after these steps, especially after a factory reset, it is very likely a hardware problem requiring professional repair (e.g., microphone replacement, speaker sealing, or audio IC repair). A short circuit is one of the most common and frustrating problems encountered in smartphone repair, often leading to a device that won't power on, or drains battery rapidly. The right magnification enables not just the doing of the repair, but the seeing of the repair, which is often half the battle won. Ensure the securing bracket, if present, is reinstalled and screwed down properly, as this bracket provides essential pressure to maintain the connection and prevent the cable from coming loose over time, especially from minor drops or vibrations. Troubleshooting software navigation bar issues is primarily a process of elimination. In conclusion, evaluating smartphone audio latency problems requires a combination of astute observation and, for precise diagnosis, objective measurement tools. It serves as the backbone, providing rigid support for the logic board, battery, screen, and all other internal components. Under Shields: Carefully remove any removable shields (often soldered, so proceed with caution). It prevents dust, lint, and moisture from entering the phone's internals through the speaker grille. Heat and Separate: Apply heat evenly to the edges of the back cover or screen for 1-2 minutes to soften the adhesive.

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