Computer boot After you have encountered screen phenomenon, boot screen is what caused it, this article for you to introduce some causes of the fault and troubleshooting methods, the following to see the specific content.
The cause of the failure of the Power-on monitor screen
LCD LCD screen screen failure may be the problem of LCD driver circuit, LCD panel power supply Circuit problems, screen contact is bad, the motherboard control circuit problems caused by. Since the LCD screen after the boot white screen, indicating that the backlight and high-voltage production circuit is working normally, but the LCD panel does not get the driving signal. If the screen disappears after the laptop shuts down and then screen again, it may be caused by a power supply board problem.
From the fault analysis, LCD LCD screen whether on or off, as long as plug in the power supply, high-voltage production circuit is always in the working state, backlight is always lit. In other words, the high-voltage generation circuit has not been controlled by the switch, that is, the motherboard to the High-voltage generator circuit issued by the switch signal lost control. Because the motherboard microprocessor sends out the switch signal generally to pass through several transistors to control, therefore the fault may be the control switch signal transistor damage.
The thinking of fault maintenance for the screen of the boot display
1, first open the LCD LCD screen shell, and then check whether the screen interface is loose or not connected well. The check screen is connected properly.
2, then turn on the notebook computer power switch, and then use a multimeter to measure the power supply voltage of the screen interface is normal. If the supply voltage is normal, go to step 5th, and if it is not normal, then check whether the safety resistor or the inductance near the output end of the screen is open or damaged. If damaged, replace the damaged components.
3, if the screen output near the safety resistance or inductance normal, and then check for LCD LCD screen power supply DC voltage conversion circuit output voltage is normal. If the output voltage is not normal, check this power circuit in the insurance resistor, PWM Controller, switch tube, inductance coil, filter capacitors and other components, and then replace the damaged components can be.
4. If the output voltage is normal, the DC-DC voltage conversion circuit will be the output end to the screen interface with damaged capacitance and other components, check and replace the damaged components.
5. If the power supply voltage of the screen interface is normal, then check the timing signal and the driving signal of the LCD driver circuit. If not, check the output signal, input signal and power supply voltage of the chip which produce this signal respectively, and determine whether the drive chip is damaged. If it is damaged, it can be replaced.
Screen boot screen maintenance is not as easy as screen black screen, need to master some of the circuit knowledge of the display, it is best to please professional display maintenance personnel to carry out maintenance.