According to your description, this issue is usually caused by a short circuit on the motherboard or a motherboard failure. When the motherboard fails to complete the self-test, the device will automatically shut down for protection.
Solution
Please replace the device's main motherboard.
The video below demonstrates the motherboard replacement process for your reference.
Precautions
Please contact the dealer or agent who sold you the device to obtain a motherboard compatible with your machine.
During use, do not hot-plug the power adapter to avoid damaging core components.
Before replacing the motherboard, please take photos of all wiring positions to avoid incorrect connections.