Why does the VGA indicator light up red but the computer can still boot up?

The VGA light is on but the computer can still boot up. This situation usually indicates a problem with the VGA connection between the graphics card and the monitor. However, the computer's main unit can still start up normally.

1. Possible causes:
1. Loose connection: The ends of the VGA cable are not firmly plugged in, resulting in unstable signal transmission and the red light being on. For example, when moving the computer or arranging the desktop, you might accidentally loosen the connection cable.
2. Damaged VGA cable: Long-term use or poor-quality VGA cables may have internal circuit breakage, affecting signal transmission.
3. Graphics card failure: The graphics card itself has a problem, even though the computer can boot up, but it cannot output the VGA signal properly. For instance, the graphics card overheats or its hardware ages.
4. Display issue: The VGA interface of the monitor is faulty and cannot correctly receive the signals from the graphics card.

2. Solutions:
1. Check the connection: Turn off the computer, reinsert the VGA cable, and ensure that both ends are firmly plugged in without any looseness.
2. Replace the VGA cable: If you have a spare VGA cable at hand, you can try replacing it to see if it solves the problem.
3. Check the graphics card: Open the computer case, check if there are any abnormalities on the graphics card, such as bulging capacitors. You can try cleaning the dust from the graphics card fan to lower the temperature. If the problem persists, you may need to replace the graphics card or send it for repair.
4. Check the monitor: Try connecting this VGA cable to another device to see if it can display normally. If the red light is still on on other devices, it is a problem with the VGA cable or the VGA interface of the monitor; if it works on other devices, it is a problem related to the computer's graphics card.