[SOLVED] I'm looking for Verykool S815 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my Verykool S815. 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.

@Nur

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 Verykool S815 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/312220/Why+does+the+toaster+lift+not+engage
Take a look at comment #152
Also, this : https://www.ifixit.com/Answers/View/523920/Can+my+power+button+be+replaced.
You can also check this video starting from minute 5:

The Verykool S815 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 Verykool S815 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 Verykool S815 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 Verykool S815 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/Wiki/Razer_Barracuda_X_Troubleshooting

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

Cleaning the Via: If the via is obstructed, carefully re-drill it with a micro-drill bit (0.1mm - 0.3mm) appropriate for the via size, ensuring it passes through cleanly. The phone is stuck in a boot loop or recovery mode, and a software flash would wipe data. Feel and Click: Does the power button feel "clicky" and responsive, or is it mushy, stuck, or loose? A lack of tactile feedback can indicate a broken button mechanism. Sudden signal loss in a smartphone, whether for cellular, Wi-Fi, or GPS, is a highly disruptive issue that can render a device largely useless for its primary functions. It's a non-invasive, zero-cost method, so it's always worth trying first. Remove External Screws: For iPhones, this means two pentalobe screws at the bottom. Loudspeaker (Bottom Speaker/Multimedia Speaker): This is the larger speaker, usually located at the bottom of your phone. Small, Sharp Scissors or Exacto Knife: For precise cutting of generic shielding material. How to enter Safe Mode: On most Android phones, press and hold the power button until the power options appear. Cut a piece of enamel-coated wire slightly longer than the distance between your source and destination points. USB-C to USB-C: The modern standard, often used for Power Delivery (PD) fast charging with laptops, tablets, and high-end smartphones. IPA Method (Preferred for highly adhered batteries): If the battery is stubbornly stuck, you can carefully apply a few drops of 90%+ isopropyl alcohol underneath the edges of the battery. In conclusion, test points are the unsung heroes of smartphone micro-repair. The symptoms can often overlap, making it difficult to pinpoint the root cause without a systematic approach. This failure isn't just cosmetic; it can render a new display unusable and, in severe cases, permanently damage the smartphone's logic board, leading to an unrepairable device. Re-inspect: Once the frame is straightened, inspect it thoroughly for any new cracks, stress marks, or areas where the metal might have thinned. ABSOLUTELY AVOID SHARP METAL TOOLS (tweezers, metal spudgers, screwdrivers) when near the battery, as they can easily puncture it. Ensure your phone's operating system is updated to the latest version, as updates frequently include audio enhancements and bug fixes. Pay close attention to apps with excessive permissions, especially those that can run in the background. Power Off: Always power off your phone completely before beginning any disassembly. From leveraging software test apps to meticulous microscopic inspection and advanced multimeter probing, a systematic approach is essential. Even a few feet of vertical movement should show a small, measurable change. Tin-Bismuth (Sn-Bi) alloys: These offer a significantly lower melting point (e.g., Sn42/Bi58 melts at 138°C), making them suitable for soldering temperature-sensitive components that cannot withstand the higher temperatures of SAC alloys. Apply heat to the edges to soften the adhesive, use a suction cup and prying tools to lift the screen. It’s not just about aesthetics; proper adhesive application is crucial for maintaining the phone’s structural integrity, protecting internal components from dust and moisture, and often, restoring its water resistance rating. Short Circuits: Exposed copper can come into contact with another trace, a component, or the phone's metal chassis, creating an unwanted electrical path. However, beneath the surface of stunning visuals, some OLED panels can exhibit an issue known as "flicker." This phenomenon, often imperceptible to the naked eye but sometimes noticeable as eye strain, headaches, or even visual artifacts, occurs when the screen rapidly cycles its brightness to achieve lower light levels. If possible, test with multiple NFC readers or tags to rule out issues with the external system. Proximity Sensor Calibration: Ensures the screen correctly turns off when the phone is held to your ear during a call, preventing accidental touches. Reduce brightness, enable adaptive brightness, or use dark mode/themes.

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