The old machine has no signal. Why?

Thank you for inviting me! There are usually several possible reasons and solutions for the lack of signal in old machines:

1. Signal coverage: Older computers usually use 2G networks, and the signal coverage is narrower than that of 3G or 4G networks. So if you are in a place where the signal is weak, or where the signal is blind, it is very likely that the old machine can't receive the signal. The solution is to try to move to a place with strong signal, such as a relatively open area or a high place.

2.SIM card problem: Old mobile phones sometimes have no signal, which is caused by poor contact or expired SIM card. You can try to take out the SIM card, clean the metal contacts and plug it back into the old machine. If the problem still exists, you can try to replace a new SIM card.

3. Equipment failure: The old machine may have hardware failure or software problems, which makes it impossible to receive signals. You can try to restart the old machine or restore it to factory settings. If the problem still cannot be solved, it is recommended that you contact the after-sales service center for maintenance or replacement of equipment.

4. Operator's problem: Sometimes the old machine has no signal, which is caused by the operator's network failure or downtime maintenance. You can call the operator's customer service hotline to find out whether there is a network fault and seek a solution.

For example, your old machine has no signal at home, but it does when it is used outside, which may be caused by poor signal coverage at home. You can try to place the device near the window or near the roadside to enhance signal reception.

I hope the above answers are helpful to you! If the problem still exists, please consider contacting the professional technical support team or relevant operators for further assistance.