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

Hi,

I'm hoping you can help me out with my Micromax Yu Ace. 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.

@Luana

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 Micromax Yu Ace 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/496436/Not+charging+after+replacing+battery
Take a look at comment #203
Also, this : https://xdaforums.com/t/voxer-your-way.2253978/.
You can also check this video starting from minute 9:

The Micromax Yu Ace 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 Micromax Yu Ace 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 Micromax Yu Ace 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 Micromax Yu Ace 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/poco-c65.4657069/

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

Thin, Non-Metallic Tool: A wooden toothpick, a plastic spudger, or a plastic flossing pick. They are often covered by a small metal shield secured by tiny screws. Identify Adhesive Location: Most modern smartphones use adhesive to secure either the screen assembly to the frame or the back glass/plastic to the frame. Charging Speed: Overheating can cause the phone to intelligently slow down its charging rate to protect the battery. Cycling Current (Boot Loops): The current rises to a certain point, then drops back to 0mA or the initial spike, and repeats. Power on the device and immediately test the camera functionality extensively. Incorrect Timing: Even if signals are present, their timing relative to each other (e.g., data valid time after clock edge) might be incorrect. Soft Brushes: Anti-static brushes with fine bristles for speaker grills, ports, and internal dusting. Pulsing or Fluctuating Current: This could indicate an intermittent short or a component trying to initialize and failing. EMI Shields: Ensure the shields over the module IC and its related circuits are present, undamaged, and properly grounded. Inspect for Cables: Before fully separating, check for any flex cables (like wireless charging or NFC) that might be connected to the back glass and the phone's logic board. Uniform Green/Pink Tint: The entire screen has a dominant green or pink hue. Secondary/Noise-Canceling Mic: Often located on the top edge of the phone, or near the rear camera module, sometimes on a separate small flex or directly on the logic board. Screen flickering on an OLED smartphone can be a multifaceted problem. Use the plastic spudger to apply gentle, even pressure directly over the center of the connector to ensure it seats properly. Volume Settings: During a call, ensure the volume rocker is pressed to increase the "in-call volume." This is separate from media volume. An unstable connection can lead to flickering, lines, and color shifts. Careful Heat Application: When using a heat gun, apply heat gently and evenly. Apply Heat: Hold the heat gun 1-2 inches away from the perimeter of the component you wish to remove (back cover, display, etc.). It's typically a small, rectangular or cylindrical module, often located at the bottom of the device or sometimes near the side buttons, connected to the logic board via a flexible ribbon cable (flex cable). If you have installed any third-party flashlight apps or camera apps, they might interfere with the built-in functionality. These shields might be soldered on (requiring hot air to remove) or clipped on. Gaming Issues: Motion-controlled games become unplayable or difficult to control. By systematically troubleshooting and carefully replacing the combined sensor flex cable, you can restore essential functionalities like automatic brightness adjustment and proper screen behavior during calls. Clean the surface of the display to remove any loose glass shards, dust, or grease. Software Glitches: Operating system bugs, outdated firmware, or misconfigured network settings. Clean Old Adhesive: Carefully scrape off all old adhesive residue from the phone's frame and the back cover. If a factory reset or flashing stock firmware does not resolve the issue, it strongly indicates a hardware failure of the internal storage chip, a repair that is typically beyond the scope of average users and often necessitates professional, costly logic board replacement or advanced micro-soldering. Start with the simplest software solutions, carefully monitoring battery performance after each change. Reliable Sources: Only download firmware, custom ROMs, or recovery images from trusted sources (e.g., official XDA Developers threads, manufacturer websites).

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