[SOLVED] I'm looking for Lenovo A3500 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Lenovo A3500. 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.

@Süleyman

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 A3500 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/upgrade-to-radio-1-20-cannot-connect-to-network.289700/
Take a look at comment #529
Also, this : https://xdaforums.com/t/problem-not-picking-up-4g-sprint-tech-cant-figure-it-out.2373263/.
You can also check this video starting from minute 6:

The Lenovo A3500 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 A3500 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 A3500 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 A3500 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/826378/Flow+Meter+Sensor+for+Culligan+CTM+Softener

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

Ensure all old solder is removed, and the pads are flat, shiny, and free of residue. This usually involves softening adhesive with heat and carefully prying open the back cover or display assembly. When this button becomes unresponsive, intermittent, or sticky, it can severely hamper the usability of the smartphone, sometimes rendering it almost unusable. Lifted Pads: A component pad might lift from the PCB, taking its connecting trace with it. Scratches: Cosmetic damage ranging from minor scuffs to deeper gouges. Backup Data and Power Off: Always back up your phone and power it off completely. It's typically housed near the top of the phone, either vertically or horizontally aligned. Microfiber Cloths/Lint-Free Wipes: For cleaning surfaces without leaving fibers. Ensure all pads are perfectly clean, flat, and free of shorts or lifted areas. Check the notification settings for specific apps (e.g., messaging apps, social media apps). Even after backing up, there are a few more critical steps before handing over your phone: Color balance aims to render true colors by correcting for the color cast introduced by different light sources. You must measure the original pad's thickness or consult service manuals. If the speaker coil itself is open (OL), the speaker is faulty, not necessarily a grounding issue. Frequent Disconnections: Wi-Fi or Bluetooth connections drop unexpectedly and repeatedly, requiring constant re-connection attempts. Overheating: Prolonged exposure to high temperatures can degrade the chip over time. Action: If the antenna cable or flex is visibly damaged or suspected, try replacing it with a known-good part. Android Safe Mode: Booting into Safe Mode disables all third-party applications. They have the expertise and tools (e.g., JTAG, EDL cables) to restore devices that can't be fixed by conventional flashing methods. Antenna System: Damaged coaxial cables, antenna flexes, or antenna connectors are common and simpler causes of "no service." Move the air blower consistently over the entire board to gently evaporate moisture. Gently lift while inserting a thin metal pry tool, then switch to a plastic spudger. Specialty adhesives play an indispensable role in maintaining the structural and electrical integrity of a repaired smartphone. Corrosion is usually indicative of liquid damage and can severely impede electrical conductivity. Major Version Upgrades: Sometimes a clean flash for a major Android version upgrade can prevent subtle compatibility issues. Method: The process varies by phone, but typically involves holding the Power button until the power-off options appear, then long-pressing "Power Off" or "Restart" to reveal the "Reboot to Safe Mode" option. Non-functional Components: If, after reassembly, a component (e.g., camera, Wi-Fi) doesn't work, it might be a damaged flex cable, a poorly seated connector, or a fault with the new motherboard itself. Use IPA on a cotton swab or microfiber cloth to meticulously clean all old adhesive residue, dirt, and debris from the speaker grille opening and the surrounding area. Time and Cost: Due to the specialized equipment and expertise required, these repairs are very time-consuming and expensive. Pins: Check the pins within the connector on the logic board for any bends, breaks, or corrosion.

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