ASUS Motherboard Light can't start solution
Reason Analysis and solution:
If we press the power button, only the power indicator light, the computer screen without any reflection, there is no alarm sound; So how should we solve this situation?
The screen is not displayed, there is no alarm sound, we can not from the post self-test function to get the appropriate information; As we all know, the computer is a complex and sophisticated product mix, so there is a problem in one link, may not be able to start the machine (we mainly talk about hardware). Therefore, if there is a black screen, no alarm sound failure phenomenon, we should be based on the computer to start the process to analyze the problem.
What is the computer startup process?
When we press the Start button, the first boot should be the power supply (because if there is no power supply, then all the parts on the motherboard will not work). But in order to ensure safe use, the power supply part takes a series of safety protection measures; therefore, switching power supply from the vibration to stability there will be a period of time delay, waiting for each group of voltage stability, the power supply each part of the output of a detection signal, this signal for high power peacetime said that the partial voltage is normal, These sections include input voltages and output voltages for each group. The result of these signals is a power good signal (also known as a power OK or pwr OK), and if the motherboard does not receive this signal, then the clock chip will continue to send the reset signal to the CPU (as we press the Reser key), the CPU will not work.
When the CPU receives a normal power good signal, does the motherboard and CPU start? In fact the motherboard at this time, but also according to the CPU's VID0-VID3 pin definition combination, the CPU provided by the VID0-VID3 signal to the source management module of the corresponding port; If the motherboard BIOS has the ability to set CPU voltage, the motherboard will set the voltage and vid's corresponding relationship in time to generate a new VID signal and send to the Power management module chip, the Power management module will be set up and through the DAC voltage will be converted to the reference voltage, and then through the field effect tube rotation conduction and shutdown, The energy is sent to the CPU through the inductance coil, and the output voltage is equivalent to the set voltage after the adjustment circuit is finally used.
Because the CPU also needs to according to their own frequency, through the IC bus to detect the frequency of the motherboard set up frequency is supported; Because the computer to carry out the correct data transmission and normal operation, no clock signal is not, when
The main function of the clock signal in the circuit is synchronization, because in the data transmission process, has the strict request to the timing, only then can guarantee the data in the transmission process does not make the mistake. The clock signal first set a benchmark, we can use it to determine the width of other signals, and the other clock signal to ensure the synchronization of the data sent and received. For the CPU, the clock signal as the benchmark, all signal processing inside the CPU to use it as a ruler, so that it determines the CPU instruction execution speed, such as the CPU itself can not adapt to the frequency of high-frequency generators provided by the high frequency, also can not work properly. Therefore, only when the power good signal is received, and the corresponding voltage to get the CPU and the corresponding clock frequency, the CPU is able to work properly, that is, to start the implementation of the BIOS program.
How to judge and solve the problem?
Because if you do not receive the power good signal, the system has been processing reset (reset) loop, so the motherboard will not be able to start, the corresponding other hardware, such as the video card also can not work, the monitor because it does not receive the video card out of the signal, so there is no display, has been At this point, we should detect the power supply, do not think the power light, it shows that the electricity is normal, because as long as there is a fault signal (this part of the circuit is not normal or not stable), the input of the power good signal is low level, that is, the source part of the fault or has not yet entered a stable shape; although the power supply indicator light is on, However, the motherboard cannot boot because it does not receive a normal power good signal. The way we detect the power supply is to use the power test that works. If the power supply is ATX type We can wire 13 and 14 feet short, if the power supply fan can be normal operation, it indicates that the power supply is intact, the fault should be on the motherboard.
Replace the normal power supply, such as the system or do not have a working image, should be based on the above motherboard boot process, test the CPU Power Management module and frequency generator. But since we cannot have sophisticated equipment to test the power and frequency modules on the motherboard (most computer enthusiasts cannot have such settings, and have the appropriate detection capabilities). So we also have to use the elimination method, that is, on other normal motherboards to test the CPU. Test troubleshooting the CPU, you should also detect the motherboard frequency setup issue. Computer enthusiasts to use or test the CPU overclocking ability, by adjusting the motherboard FSB mode (the current CPU has been locked frequency, can only set the FSB, and can not set the frequency multiplier), to adjust the CPU's working frequency. If the CPU can not adapt to high operating frequency, although the power supply is normal, the motherboard can not start.
Troubleshooting Other hardware issues, is the system still not bootable?
If the hardware is all normal (tested), then after the post on the self-test, the CPU will start from the address of the ffff0h to execute instructions, this address in the system BIOS address range, whether the award BIOS or the AMI BIOS, put here is just a jump instruction, Skip to the real boot code at the system BIOS. Since the BIOS is a bridge between the operating system and the hardware, providing the lowest-level, most direct hardware control for the computer, the original operation of the computer is done according to the contents (instructions) that are cured in the BIOS. Therefore, if the BIOS file is damaged or the BIOS chip is damaged, it will directly affect the boot of the motherboard.
How can I tell if the BIOS is corrupted?
It is difficult to determine whether the BIOS is normal, because without a test tool such as a programmer, it is impossible to judge whether the BIOS file or the chip is normal through the senses, for ordinary users, only find a maintenance provider to solve.
If the screen displays the BIOS ROM checksum Error-system halted (the BIOS program code finds an error in the sum check (checksum), the checksum sum fails when the BIOS is read, so the machine cannot be restarted.
This problem is usually caused by incomplete BIOS program code updates, and the workaround is to brush the bios of the motherboard to burnout.
What is the total BIOS checksum checksum?
Checksum (checksum summation) is a simple and easy integrity control method in the field of data processing and data communication. Combine all the bytes of data with a series of arithmetic or logic operations to get a checksum value. The checksum value can be computed in the same way later and compared with the last computed value. If it is equal, the data is unchanged, and if not, the data has been modified.
Other reasons for the system not to start?
Typically, after the BIOS is transferred, on the computer when the detection, initialization system equipment, loading the operating system and dispatching the operating system to the hardware issued by the BIOS, and some hardware detection can also be post self-test to show whether the work is normal, whether some of the problems before the boot can be resolved. Actually, because after the CPU is transferred into the BIOS, but also need to detect 640K basic memory and the interrupt of each slot; Although the memory error post can be prompted by the sound of the alarm, but such as memory internal damage or short circuit, will cause the motherboard partial short-circuit, or can not start the machine; therefore, for the system does not display, No alarm sound processing, in addition to basically exclude the way, but also need to accumulate experience in peacetime.
Due to overclocking, the machine can not start, how should be resolved?
For Overclocking, unable to start the machine, there are two ways to purge frequency settings, one is to clear the CMOS settings (for the way you can set the CPU operating frequency in the CMOS), as long as the CMOS purge jumper is found on the motherboard (typically, next to the motherboard battery, for the 13-pin jumper), after the CMOS is removed, Re-restore the jumper position to resolve. Another way is to reset the frequency set jumper (the way to set the CPU frequency through the motherboard frequency jumper), just reset the normal frequency according to the manual.
What kind of detection tool is the motherboard debug card?
Motherboard debugging card is a professional hardware fault detection equipment, using its own hardware circuit to read the 80H address of the post code, and decoder decoding, and finally by the digital LED indicator code one by one display, the principle and post self-test is consistent. This allows you to use the 16 code shown on the debug card to determine where the problem is in the hardware, rather than relying on a few monotonous warnings from the computer's motherboard to make a rough judgment of the hardware error. And since the debug card is using its own BIOS post program, to read the post code for the diagnostic port, so it is not limited by the motherboard BIOS chip and can be diagnosed properly if the motherboard BIOS is damaged, and the working state of each group is displayed using the light-emitting secondary tube of the debug card itself. It allows you to see if hardware testing is not through memory or CPU, or other hardware, to easily and visually solve difficult motherboard problems.
The current motherboard debug card usually comes with the ISA and PCI two interfaces. Can be conveniently used in any one of the motherboards, and the plug will not burn the motherboard or debug card (very suitable for the novice); The card has a two digit lde tip light, if the computer can not start to plug it into the corresponding slot in the faulty motherboard, after the power supply, Depending on the number of LEDs that are finally stagnant, refer to the failure list manual that came with the card to know where the motherboard failed. And the latest debug card,
You can run the detection lamp by debugging the motherboard of the wrong card to detect the failure of the motherboard itself or other hardware on the motherboard.
How do I use the motherboard debug card?
First plug the Debug card into the failed motherboard, CPU, memory, expansion cards are not plugged in, only plug in the motherboard of the power supply, at this time, the main vibration lamp should be bright, otherwise the motherboard does not start vibration, the reset light should be bright half a second after the extinction, if not bright, the motherboard without reset signal and can not be used, if illuminated steady, the motherboard is always in the reset state, , beginners often put the speed switch as a reset line inserted into the reset pin, resulting in the reset lamp often bright, reset circuit damage will lead to this fault;
The frequency-division signal light should be bright, otherwise, the frequency division has faults; +5v, -5v, +12v, -12v (new card more +3v, -3v) four (six) power led should be bright enough, not bright or brightness is not enough, indicating that the output of switching power supply is not normal, or the motherboard to the power supply short-circuit or open circuit; The BIOS light is normal because no CPU is not lit, but if plugged into a good CPU, the BIOS lamp should not be a regular flashing, otherwise the CPU bad or jumper incorrect or motherboard damage. DEBUG 2000 of this function is quite effective, like -5v, -12v voltage value in the PC components are rarely used, the new or used PC power, the -5v and -12v may have been damaged, usually peaceful, out of the problem will make you headache.
You can now easily solve this problem by using the instructions on the debug card. After the above simple failure is eliminated, the relevant expansion card plug (generally only composed of the smallest system), according to the code displayed after the boot, you can directly find the problem of accessories, so as to facilitate the installation of hardware errors, such as memory, graphics, CPU and other hardware contact errors, BIOS, CPU Cache functionality error, and so on.
Why can't I start my computer with a USB disk?
This is mainly due to the fact that the USB boot option in the BIOS is turned on at the end or is properly set. After entering the CMOS settings, in the system boot sequence, there are "FDD USB" and "HDD USB" option, this is the USB boot option, so the option system boot sequence for USB set first. However, some old motherboards do not support USB boot and therefore cannot use the flash drive.
How do I start a computer using a USB mobile hard drive?
To start the computer with a USB hard drive, you must have the motherboard support USB settings to boot, and now the USB boot is mainly USP-FDD, Usb-zip, USB-HDD and Usb-cdrom. To use a USB removable hard disk as your boot disk, you must set the system boot order to USB-HDD in the CMOS settings.
How do I troubleshoot my new motherboard if I can't find the IDE settings?
This is due to the increasing capacity and speed of the current hard drive, both power consumption and power supply requirements are greatly increased, and the hard drive from shutdown to startup (power on) to initialize the completion of the time it takes, However, there is no increase in the time that the motherboard BIOS performs from power-on to detecting the IDE device. This results in the inability of the motherboard to detect the hard drive or the delay in detecting other IDE devices because the hard drive is too time-consuming to detect, especially if the connection has two or more hard drive systems, If the reset button is pressed at this point, the failure will not occur because each IDE device has completed initialization work. In this respect, as long as the open machine into the CMOS setup interface, find the "Boot Delay Time" option (note: Some manufacturers of the BIOS is "IDE Delay Times"), the appropriate extension of its delay.