[SOLVED] I'm looking for VTOUCH V705-S repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my VTOUCH V705-S. 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.

@Love

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 VTOUCH V705-S 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/399-update-arrives-to-honor-8-frd-l09c185-officially-in-middle-east.3818424/
Take a look at comment #1381
Also, this : https://xdaforums.com/t/reboots-on-cm7-nightlies.980868/.
You can also check this video starting from minute 3:

The VTOUCH V705-S 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 VTOUCH V705-S 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 VTOUCH V705-S 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 VTOUCH V705-S 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/407686/How+do+I+program+my+dish+sat+remote+to+turn+on+my+t.v.

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

Final Test: Power on the phone and perform a thorough test of the ambient light sensor and all other functions. Connect the black probe to a known good ground point (GND) on the PCB (e.g., a large metal shield, a screw hole). Use fine-tip tweezers, a magnetic tool (if applicable), or even a strong adhesive tape to lift and remove every single shard. Ensure all grounding contacts (e.g., spring contacts, screws, metal clips) are clean, corrosion-free, and making firm contact. Baseband issues are notoriously complex and often require specialized knowledge and equipment for repair. Apply a thin, even layer of no-clean liquid flux to the cleaned pads on the motherboard. Carefully disconnect the camera module flex cable(s) and gently remove the camera module(s) from their housing. You'll need the Odin software and official Samsung firmware (.tar.md5 files). In a normal, interference-free environment, the total magnetic field strength (often labeled as "Magnitude" or "Total Field") should be relatively stable and typically fall within the range of Earth's magnetic field (e.g., 20-70 µT, though this varies slightly by geographic location). Legality and Terms of Service: Respecting manufacturer warranties, software licenses, and local laws. Fuses provide crucial overcurrent protection by sacrificing themselves to open a circuit, while various types of diodes offer unidirectional current flow, voltage regulation, and rapid clamping against transient voltage spikes like ESD. Intermittent Charging: The phone charges only when the cable is held at a specific angle or frequently connects and disconnects. Cleaning: Thoroughly clean the smartphone PCB with 99% IPA to remove any old flux residue, dust, or contaminants. Some gaming phones may have software settings to calibrate or re-map dedicated buttons. Incorrect APN settings are a common cause of slow or non-existent data. Once you have tools under a significant portion of the battery, you can gently lift it from the frame. Avoid Liquid Exposure: Water and other liquids are notorious for damaging audio components. Placement: Once bent, gently guide the cable into its final position within the phone's chassis. Carefully remove any metal shielding covering the DSP and surrounding components. Read Instructions Carefully: Follow unlocking and flashing guides meticulously, specifically for your device model. After cleaning, the logic board must be completely dry before reintroducing power. Recent Trauma: Has the phone been dropped, bent, or subjected to any significant physical impact recently? A sudden appearance of Wi-Fi issues immediately after such an event strongly points to hardware damage, including antenna detachment. Fine-Tipped Tweezers: For manipulating small screws and delicate flex cables. However, when attempting to set up Face ID in Settings, you will almost certainly encounter the "Face ID is not available" error, confirming the pairing restriction. They function by filling microscopic gaps and creating a compressive seal between mating surfaces. Front Camera and Sensors: These might be in a bracket that needs to be transferred. Battery Health: A severely degraded battery can sometimes cause heat issues, although this usually manifests as rapid drain or swelling rather than direct thermal throttling of the SoC. Schematics and Boardview tools are essential for identifying faulty ICs (Integrated Circuits) on the motherboard. Avoid chemical residue: Some canned air sprays release a cold, wet propellant if held upside down or sprayed too long. If a pin is broken or severely bent, the SIM card reader connector on the logic board is damaged and would require a complex microsoldering repair, which is usually only performed by specialized technicians.

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