a. Hard disk burnout after power failure!
After the computer is turned on and ready, it will send a PG (Power Good) signal to the motherboard. Upon receiving this signal, the system will boot and the hard disk will start to read and write. When at this point there is low voltage and insufficient power, the hard disk will experience an abnormal rotation speed due to which the magnetic heads of the hard disk cannot be suspended to their normal position and will scratch the disk.
b. Unstable screen picture
Using an inferior quality power supply may influence the display, giving a rippled or unstable picture. If a problem with the display card is ruled out, the problem most probably lies in an unstable power supply to the motherboard.
c. Overload causing burnout of chips, cards and/or motherboard.
Sudden cutoff from power supply or computer shutdown due to power failure. None of the peripheral hardware, nor the CPU, memory, motherboard and display card, will be able to work normally. As the +5V and +12V output terminals of an inferior quality ATX power supply use the same voltage regulator circuit, it may occur that a higher +5V load causes a higher +12V output voltage. Since most chips, cards and motherboards require a +12V power supply, a substantial increase in the +12V voltage of an inferior quality power supply may lead to burnout of these components.
d. Excessive noise of sound card
Inferior quality power supplies are well below the standard for electromagnetic screens and current output purity. In such a poor environment, they can hardly be expected to produce a nice sound. False and deceitful label specifications of inferior quality power supplies lead to unexpectedly frequent re-starts of the computer.