It is common for companies to place a data cap on the devices they provide to their employees, to control costs. If a user has exceeded the data cap, the phone may no longer allow internet browsing over a cellular connection. This is usually because the cellular data usage has exceeded the allotted amount for the particular plan the device is on, and the service provider has temporarily suspended the data connection.
It is unlikely that the child accidentally connected to a neighbor's WLAN because this would not affect the cellular data connection. Similarly, it is unlikely that the company's group policy has disabled the device, as this would likely affect all devices under the same policy. If the device's plan has been unpaid, the service provider would likely temporarily suspend all services, not just the cellular data connection.

Reinstalling RAM in different slots addresses possible issues with dual-channel configurations. If not installed correctly, the system might not recognize the full capacity. This solution is immediate and doesn't incur extra costs, unlike replacing hardware.

By running the specified tests (ping of the default gateway, ping of the localhost, and tracert of the IP address of the default gateway), the technician can find connection latency and the subnet mask of the network.
Connection latency: The time it takes for a ping or tracert command to send and receive a response helps in determining the latency in the network connection. Higher latency values can indicate delays in communication over the network.
Subnet mask of the network: The ipconfig command, which the technician would initially run to perform these tests, provides various details about the network configuration, including the subnet mask. The subnet mask is essential in determining the network and host portions of an IP address, which is crucial for networking and troubleshooting connectivity issues.

The technician should ensure that a VGA cable is connected properly between the monitor and the computer. A VGA cable is a type of video cable that carries analog signals. If the cable is loose, damaged, or not plugged in correctly, it can cause the monitor to not display any image or show distorted colors.