Lamtto DC21 4-Channel Dash Cam: User Guide & FAQ
🚗 Dash Cam DC21B – Complete Setup & Troubleshooting Guide
Welcome to the DC21B support page. Here you'll find everything you need to get your dash cam working perfectly, from installation to solving common issues.
🎥 Reference Videos
▶️Function Setting Introduction
▶️How to install a rear camera
How to Connect to WiFi (Step-by-step video guide)
📱 Download the App
Search for the app in the Apple App Store or Google Play to connect and manage your dash cam remotely.
🔋 Power & Recording Issues
Why does the Dash Cam shut off automatically while driving?
Please follow these troubleshooting steps carefully:
Start with these quick checks:
Turn off features like Screen Saver in the settings menu. This feature only turns the screen black but recording continues normally.
Make sure the original car charger is firmly plugged into your cigarette lighter socket. The charger's indicator light should remain steady. If it flashes, please contact us.
Check the SD card:
Remove the SD card and power the dash cam using the original car charger.
If the problem stops, the SD card may be causing the issue. Try formatting the card or replacing it with a U1 or U3 class card.
Test without the rear camera:
Unplug the rear camera and see if the dash cam still shuts off while driving.
If the issue stops, the rear camera may be defective. Please email us your order number and troubleshooting results for a replacement.
Test with an alternate power source:
Bring the dash cam indoors and use a USB cable with a 5V 3A power adapter (plugged into a wall socket). Do not use a computer as the voltage may be too low.
If the issue stops, the car charger may be defective. Contact us for a replacement.
If none of these steps help, please email us at DC@yooomail.com with your results.
What should I do if the screen freezes or buttons don't work?
For a frozen CarPlay screen:
Clear background app data on your phone.
Reset and restart your CarPlay system.
Try connecting a different phone to see if the issue is related to compatibility.
For unresponsive buttons:
Turn off the device, disconnect the rear camera, then restart. If fixed, we will send you a new rear camera.
If not, remove the SD card and restart. If fixed, replace or format the SD card.
Try resetting the device to factory settings.
If nothing works, contact us for a final solution.
🔧 Installation & Setup
How do I install the hardwire kit?
Professional installation is strongly recommended. Please follow these steps carefully:
Connect the BAT+ (B+) fuse tap to the positive terminal of a constant fuse slot. This provides power even when the engine is off.
Connect the ACC fuse tap to an ACC fuse slot that only powers on with the ignition.
Ground the black wire by screwing it securely to any non-coated metal bolt in your vehicle.
Plug the hardwire kit into your dash cam.
Important safety tips:
Turn off the ignition before starting installation.
Do not use fuse slots that power critical components like airbags.
Use proper tools to test polarity and grounding.
How can the rear camera automatically turn on when reversing?
Make sure the red cable from the rear camera is securely connected to the positive lead of your reverse lamp. This wire only activates when the car is in reverse gear. If the cable is properly connected and it still doesn't work, please contact us for a replacement.
The front camera is severely tilted. What should I do?
Don't worry. The front camera can be rotated upward, downward, left, and right. It also allows for small-angle planar adjustments. Gently adjust its direction until you get the perfect view.
💾 SD Card & Recording
Does the camera continue recording after the SD card is full?
Yes. Enable "Loop Recording" in the settings. When the storage is full, the camera will automatically overwrite the oldest files with new recordings.
Why does my SD card fill up so quickly?
The G-Sensor and Parking Monitor features lock videos whenever the camera detects a shake or impact. These locked videos are crucial as evidence but are never overwritten automatically. If your SD card fills up with locked clips, you will need to manually delete or format the card.
How to manage locked videos more effectively:
Adjust the G-Sensor sensitivity to Middle or Low in the settings. This reduces how easily the camera locks videos, preventing the SD card from filling up too quickly.
Important safety reminder:
Do not disable the G-Sensor or Parking Monitor completely. These features protect you by preserving critical evidence in case of incidents. Disabling them may endanger your safety.
Why doesn't my dash cam automatically record when I start the car?
This is usually related to the SD card or settings. Try these steps:
Disable the "Motion Detection" feature.
Format the SD card to FAT32 on a Windows PC, then reformat it in the camera.
If the issue continues, contact us at DC@yooomail.com.
🔌 Power & Connections
Can I plug this into a USB phone charger?
Yes, you can use a USB charger with a cable. However, the dash cam requires a 5V 2A power supply. The original car charger is recommended as it provides the correct output.
Do I need to purchase additional parts for parking monitoring?
No. Your order includes a hardwire kit. Once installed correctly, the "Parking Monitor" option will appear in the settings menu. Enable it, and the feature will work when the car is parked.
Does the dash cam record when the ignition is off?
Yes, it can record short 10-15 second clips when the parking monitor feature is activated and detects motion or a shake. This uses the built-in mini battery.
🔑 Password & Resets
How to reset the password?
Press the "Reset" button on the device. After resetting, the password will return to the default: 12345678.
📞 Need Further Help?
Our support team is ready to assist you. Please email us at DC@yooomail.com and include:
Your order number
A clear description of the issue
What troubleshooting steps you have already tried
We are committed to resolving your issue and appreciate the opportunity to make things right.