When the computer is turned on, there are two beeps on the main unit. Why?

The self-test two short sounds reflect that there is a problem with the motherboard, but the problem is not big, and the system can be solved by automatic adjustment, but it is best to restore the BIOS system: turn off the power, remove the button battery of the motherboard, change the jumper pins next to it for 5-10 seconds, and then put it back in place, and restart it. Here's what some computer ringing alarms mean:

1 Short: The system starts normally. This is something we hear every day and it also shows that there is nothing wrong with the machine.

2 Short: General error, please go to CMOS setup and reset the incorrect option.

1 Long 1 Short: There is an error with the RAM or motherboard. Try to change the memory, if it still doesn't work, you have to change the motherboard.

1 Long 2 Short: Wrong monitor or graphics card.

1 Long 3 Short: Keyboard controller error. Check the motherboard.

1 Long 9 Short: Motherboard flash RAM or EPROM error, BIOS corruption. Try a different block of flash ram.

Constant ringing (long sound): The memory module is not plugged in tightly or damaged. If it still doesn't work, you can only replace a memory module.

Ringing: The power supply and monitor are not properly connected to the graphics card. Check all the plugs.

Repeated short rings: Power supply issues.

No sound, no display: Power issue.

My house rings, and there's no reason for it.

Computer self-test, everyone's ringing.

The sound of the computer clicking twice when it turns on is usually a signal from the motherboard during a post. This sound is often used to indicate the results of hardware detection and self-test, and to help the user identify the problem. Depending on the situation you described, there are several possible causes of the fiber:

1.BIOS self-test: When the computer is turned on, the motherboard will perform a self-test, and this process is usually accompanied by some sound prompts. Different motherboard brands and models may have different sound encoding, so the sound you hear may be different from other motherboards.

2.RAM issues: The motherboard's self-test process also involves the detection of memory (RAM). If there are any memory-related issues, such as bad sockets or mismatched memory modules, it may cause the motherboard to sound accordingly.

3.Keyboard issues: Sometimes, the sound of keys when the computer is turned on can come from the keyboard, especially some mechanical keyboards. In this case, the sound is generated by the mechanical structure of the keys and has nothing to do with the motherboard self-test.

Since you have replaced the motherboard, it is recommended that you first check whether the connection between the motherboard and the memory is secure, and make sure that the memory modules are inserted into the motherboard slot correctly. If your computer is working properly and there are no other issues, then these sounds are probably normal. However, if you encounter other abnormal conditions, such as frequent freezes, blue screens, or boot difficulties, then it is recommended that you consult a professional or technical support for further troubleshooting possible hardware failures.