[SOLVED] I'm looking for Samsung SM-N975J Galaxy Note repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Samsung SM-N975J Galaxy Note. 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.

@Inge

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 Samsung SM-N975J Galaxy Note 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/Guide/How+to+Replace+a+Penny+Board+Wheel/158151
Take a look at comment #212
Also, this : https://www.ifixit.com/Answers/View/151421/Cannot+get+apps+for+my+iOS..
You can also check this video starting from minute 10:

The Samsung SM-N975J Galaxy Note 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 Samsung SM-N975J Galaxy Note 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 Samsung SM-N975J Galaxy Note 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 Samsung SM-N975J Galaxy Note 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/589890/Cannot+boot+past+Apple+logo,+after+screen+replacement+kit.

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

Reduced Inductance/Capacitance: Crucial for high-frequency signals, minimizing interference and signal degradation. If at any point you feel uncomfortable or out of your depth, it is always safer to seek professional assistance.## 5. Carefully remove the old coil (often secured with adhesive) and its flex cable. Look for balanced differential signals (one line going high while the other goes low), and ensure there's no common mode noise. Cause: This occurs when the liquid crystals, which control pixel colors, retain their orientation for too long after displaying a static image. This alters the battery's voltage discharge curve, making it harder for the BMS to accurately estimate the remaining charge, especially at lower percentages. OS Bugs/Updates: Software glitches or incomplete updates can sometimes cause system services to run excessively. Scratched Lenses: Using abrasive materials or excessive force can permanently scratch the delicate camera lens. A malfunctioning power flex cable renders the physical power button unresponsive, which can be incredibly inconvenient, effectively trapping you in a non-booting state, preventing you from turning off the device, or waking the screen. When the heatsink is pressed down, the pressure will evenly spread the paste. Visual Inspection: Examine the charging port itself for dirt, debris, lint, corrosion, or bent pins. Full Reassembly: If the test is successful, carefully reassemble the device. Carefully reassemble the rest of the smartphone (reconnect the battery last). Model-Specific Guide: Always use a detailed repair guide for your exact phone model. Disconnect Old Motor: Carefully disconnect the motor's flex cable from the logic board or pry up its spring contacts. Crucially, back up all important data before performing a factory reset. Heating Mat/Pad: Provides consistent, even heat to the entire device, which can be safer for some applications, especially for softening stubborn adhesive over a larger area. Inspect the re-laminated display under bright light for any dust, bubbles, or imperfections. Power Management IC (PMIC) or Charging IC: The charging process is managed by dedicated integrated circuits (ICs) on the motherboard. Carefully reconnect the camera flex cable, ensuring it's seated perfectly flush in its connector. Final Polish: Once the scratch is gone, use a clean part of the cloth to buff the area to a high shine. This allows the pressure-sensitive adhesive to form a strong, permanent bond. A clean surface is essential for the new adhesive to bond properly and maintain water resistance. For iPhones, the display assembly opens from right to left like a book. Detecting internal smartphone rattle noises is an important diagnostic skill for any smartphone user or technician. Take Photos: Documenting screw locations with photos before removal can be a lifesaver if you lose track. Earpiece speaker: Make a normal phone call and hold the phone to your ear. When the screen isn't securely seated within the phone's frame, it creates unsightly gaps, exposes internal components to dust, moisture, and potential damage, and significantly increases the risk of the screen detaching completely or cracking further upon impact. Look for lint, dust, or debris, as well as bent, broken, or corroded pins. Embarking on a smartphone repair, whether for a cracked screen, a failing battery, or water damage, requires more than just mechanical aptitude; it demands the right set of tools.

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