First, if the hard disk light stays on when the screen is stuck, the main reasons are:
1, the hard disk has a bad track, often accompanied by a crash, or abnormal startup, or difficult startup failure;
2. The host power supply voltage of +5V is low (lower than +4.85V). The mechanism is that under this (low) voltage, the magnetic head can't work normally, reading is difficult, and the speed of the whole machine is reduced.
Second, if the hard disk light flashes quickly when the screen is blocked, it is generally:
1, there is something wrong with the filter circuit of the hard disk power board;
2. The host power supply voltage of+12V is low (lower than+1 1.80V), which causes the rotation speed of the hard disk drive motor to decrease, and the magnetic head can't read data, making the hard disk indicator light flash quickly (repeatedly re-reading data);
3. If the hard disk indicator light is dim when the screen is stuck, it means that there is something wrong with the power supply circuit and/or control circuit of the hard disk main control board;
In short, the landlord should make a preliminary judgment according to the state of the hard disk indicator light, and finally find out the real reason for the slow running speed of the whole machine.