[SOLVED] I'm looking for Samsung E350 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Samsung E350. 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.

@Tanja

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 E350 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/will-c900-still-receive-ota-updates.3384748/
Take a look at comment #1284
Also, this : https://www.ifixit.com/Answers/View/776985/What+can+I+substitute+to+charge+this+with.
You can also check this video starting from minute 7:

The Samsung E350 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 E350 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 E350 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 E350 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/q-galaxy-s5-just-rebooted-with-an-unlocked-lock-saying-custom-powered-by-android.2785430/

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

Remove Remaining Modules: Systematically remove all other components from the old display bracket: Clean the Tray (Optional): If the tray appears dirty, you can gently wipe it with a lint-free cloth. Adhesive Strips (if needed): For re-securing the back cover or display. You can gently press down on the can with tweezers as it cools to ensure good contact. Kapton Tape: Heat-resistant tape to protect nearby components during soldering. Plastic Opening Tools (Spudgers): Useful for disconnecting any flex cables. Unscrew the tiny Phillips screws holding this shield and carefully remove it. iPhones (older models with Home button): Press and hold both the Home and Power/Side buttons simultaneously until the Apple logo appears. If the screen is already lifting due to battery pressure, you might find an easier entry point. Align it precisely over the pads on the logic board, ensuring its orientation matches the original (this is where your reference photo helps). If part of the display assembly, inspect the area around the flex cable connection for any signs of physical damage or corrosion. Verify Non-Conductivity: Double-check that your chosen paste is non-conductive. Remove the motherboard from the phone frame, disconnecting all flex cables, and place it on your anti-static mat. In such cases, careful re-evaluation and potential re-opening might be necessary. Many Android manufacturers provide hidden "Service Menus" or "Hardware Test Modes" accessible by specific dialer codes (e.g., `#0#` for Samsung, `##6484##` for Xiaomi, or `##4636##` for general Android info, though sensor tests vary widely). Remove any dust, debris, or old adhesive residue using isopropyl alcohol and a lint-free cloth. Go to Settings > System > Reset options > Erase all data (factory reset). Apply a small amount of heat to the back of the phone where the battery sits (this helps soften the adhesive). It's possible a trace on the motherboard was damaged beyond simple repair, or the replacement SIM card reader itself was faulty. Any residual adhesive, plastic fragments, dust, or grime left behind will compromise the seal of the new window and could potentially affect signal integrity or aesthetics. Antenna Contact Points: Wi-Fi, Bluetooth, and cellular antennas often make contact with specific ground points on the motherboard. Encountering a "blue screen of death" (BSoD) on a smartphone, while less common than on desktop computers, is a clear indicator of a critical system failure. While it requires careful attention to detail and patience, by following these steps, you can successfully restore your phone to its former energetic self, saving money and contributing to a more sustainable tech future.### 10. Cellular Antennas: For 2G, 3G, 4G LTE, and 5G, often located at the top and bottom of the phone. Always proceed with caution and prioritize safety, especially when dealing with delicate internal components and heat. Remove Internal Screws (if needed): With the battery disconnected and the phone fully open, you can now access the internal components. Cleaning Cloths: Lint-free microfiber cloths, lint-free wipes, cotton swabs (Q-Tips). It's important to rule out software issues, network provider problems, or a faulty logic board/antenna module before concluding that the cables are the culprit. Remove SIM/SD Card: Take out the SIM and any external storage cards to prevent damage or loss. It wipes user data and app data, but uses the existing OS installation.

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