[SOLVED] I'm looking for KRONO Net 1100 repair guide or schematics (free) - Phones & Tablets Forum

Hi,

I'm hoping you can help me out with my KRONO Net 1100. 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.

@Katerina

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 KRONO Net 1100 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/samsung-galaxy-s2-bootanimation-guide.1305042/
Take a look at comment #620
Also, this : https://xdaforums.com/t/q-problem-with-player.3161988/.
You can also check this video starting from minute 9:

The KRONO Net 1100 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 KRONO Net 1100 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 KRONO Net 1100 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 KRONO Net 1100 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/622341/The+Isopropyl+alcohol+that+we+use+on+circuit+boards

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

Research Your Phone Model: Find a detailed repair guide or teardown video specific to your smartphone model (e.g., on iFixit, YouTube). Clean the Area: Use IPA and a lint-free cloth/cotton swab to clean any old adhesive residue, dust, or debris from the sensor's housing and the display's sensor window. Hardware Failure: Faulty Wi-Fi module or cellular modem (less common). Perform a general visual sweep of the entire logic board under magnification. Component Damage from Heat: Overheating can damage sensitive internal components. This is a very common cause of flex cable failure, especially at the button switches themselves. Successful via repair can resurrect an otherwise dead or malfunctioning smartphone, extending its lifespan and showcasing the highest echelon of repair expertise. Alternative: Some technicians prefer adding low-melt solder to the existing joints to lower the overall melting point, then use hot air or a specialized pre-heater. Carefully disconnect all flex cables and remove all components from the motherboard. Camera Bracket/Housing: A plastic or metal frame specifically designed to hold all these components in their precise positions relative to each other and the display cutout. The goal is to create flat, clean, and shiny pads without lifting any traces. Never poke directly at the fine mesh or the speaker diaphragm behind it. Reset Network Settings: This option (found in system settings, usually under "System" or "General Management") resets all Wi-Fi, Bluetooth, and cellular network settings. Cleanliness is Crucial: A pristine workspace and meticulous cleaning of the sensor area are paramount for optical sensors. This is the most common reason for chip-off recovery failure on newer devices. Booting the phone into safe mode can help identify if a recently installed third-party application is interfering with camera operations. Remove any shielding or components obstructing access to the NAND chip. Repairing a smartphone with a damaged antenna amplifier is a challenging task, often requiring advanced diagnostic and repair skills. For Back Cover Removal: Use a heat gun to gently heat the edges of the back cover to soften the adhesive. Reinstalling Android firmware, often referred to as flashing stock ROM, is a powerful troubleshooting step for a wide range of smartphone issues. Remove all screws and connectors to fully extract the logic board from the phone housing. The primary chemical cleaning agent for water-damaged electronics is 99% Isopropyl Alcohol (IPA). Gather Tools: You'll need specialized tools: prying tools, suction cup, small screwdrivers, heat gun/hair dryer (to loosen adhesive), spudgers. Voltage Injection: Inject a low voltage (e.g., 0.5V to 2V, depending on the rail) at a limited current (e.g., 1-3A) into the shorted rail. Repairing such damage, often requiring microsoldering, is a highly skilled procedure that can salvage an otherwise expensive motherboard. In conclusion, inspecting smartphone vibration motor alignment involves a combination of external symptom analysis and, if necessary, careful internal hardware examination. Unlike the external back panel or display, the mid-frame provides crucial structural integrity, houses the logic board, battery, and various modules, and often includes mounting points for antennas and internal buttons. If the bend is severe or you're uncomfortable with the complexity, it's always wise to consult a professional repair service. Rubber Gaskets/Foam: Are there any rubber or foam dampeners present? Are they torn, degraded, flattened, or missing? These are crucial for proper vibration transfer and noise reduction. Poor reception in certain areas: Works in cities but drops out in rural areas, or struggles with indoor reception.

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