Troubleshooting of Improper CMOS setup

The motherboard's fault is strange, although most of the time the computer can not start normally is caused by the motherboard hardware damage, but due to improper settings caused by the failure of the normal startup is not uncommon. We know that the bios of the motherboard is also the BIOS of the entire system, and if it is not properly set up, then this problem can occur.

The motherboard's fault is strange, although most of the time the computer can not start normally is caused by the motherboard hardware damage, but due to improper settings caused by the failure of the normal startup is not uncommon. We know that the bios of the motherboard is also the BIOS of the entire system, and if it is not properly set up, then this problem can occur. For example, when Windows 98 o'clock is installed, the "Virus Warning" (Virus warning) option in BIOS Features Setup (BIOS feature settings) is set to "Enabled" (allowed) by the "Disabled" (disabled) At the initial stage of the installation Win98, a black rectangular area appears on the screen, as if there was a hint, and then stopped installing. We can resolve the problem by simply setting this option to "Disabled" (forbidden). Also pour such as, CMOS parameter is lost, boot prompt "CMOS Battery state is low", sometimes can start, use after a period of time freezes. This means that the battery on the motherboard is out of power, then we need to replace the battery can be resolved.

But there are also many times when we can't fix the problem after replacing the battery or having a new BIOS setup. This occurrence of this failure, but is caused by the following several reasons.

First, the CMOS settings in the replacement battery will not be able to save soon after

Symptom: A Pentium 4 2.4GHz pc with a motherboard for the ASUS 865PE chipset. The use of more than three years did not appear any problems. After the recent boot found that the clock can not be saved, into the CMOS reset time, again power off the opportunity, the clock still return to zero. As a result, the motherboard of the battery ran out, after the battery, the use of less than one months to appear this failure again.

Failure reason: generally because the motherboard battery voltage is not enough to deal with: replace the battery can be. If some of the motherboard battery replacement, can not solve the problem, you should first check the motherboard CMOS jumper is a problem, sometimes because the motherboard on the wrong set of CMOS jumper to clear options, or set into an external battery, also makes the CMOS data can not be saved.

But this failure did not find the jumper set is not correct, in general, the new replacement of the battery, at least with a yinianbanzai, but this is only one months time, the battery is depleted? So the judge is the motherboard circuit has problems. In general, if the battery is replaced, time is not long and the same phenomenon, it is likely to be the motherboard leakage, through careful examination of the motherboard on the diode and capacitance, found in the CMOS chip around a battery has significantly burned traces, with soldering iron after the use of a multimeter detection, found that this capacitor has been damaged, After replacing a capacitor with the same capacity, the fault is resolved.

Two, the CMOS setting is still unable to save after replacing the battery

Failure phenomenon: A desktop compatible machine that uses more than three years, recently found that the clock can not save, each boot will automatically return to zero, into the CMOS reset, still can not be guaranteed, so that the motherboard for the CMOS power supply battery without electricity, replace the new battery, the setting is still unable to save, power after the various settings automatically to zero.

Failure Analysis: The basic settings of the computer, such as time, can not be saved. Automatically zero after each boot. This situation is generally considered to be the motherboard of the battery is no electricity, then only replace the battery can be resolved. After replacing the battery, the setting is still unable to save, so suspected that the battery has a problem, the battery is removed, measured with a multimeter, the voltage is normal and did not fall, it seems that the battery is no problem. Then carefully check the motherboard used to install the battery socket, found that the contact with the battery has some minor rust on the reed, with fine sandpaper polished clean reinstall after the use of normal, failure disappeared.

Analyze the cause of the failure, may be after the summer, the air humidity is larger, and he wants to strengthen the ventilation and heat dissipation so the chassis open, resulting in the battery contact point rust, resulting in poor contact, so that the BIOS settings can not be stored normally, but did not make the settings are completely lost, so when the boot did not prompt the BIOS

Third, the motherboard battery cannot cause the computer not to start

Symptom: A friend of a computer, recently failed: Press the power button, the computer has no response, repeatedly press the power switch is still invalid. After a preliminary analysis, it is likely that the power supply part of the problem, not enough power (inferior power of the "patent") is a short circuit switch, with a good idea to take a variety of tools to go straight to the friend's residence.

Failure Analysis: As the friend said, no matter how to press the POWER switch (socket contact good and verify that there is electricity), the computer is like a wooden person "motionless." The computer does not have any alarm sound, the motherboard does not appear to be loaded to the required voltage, the power supply fan also does not move, it seems that the computer simply cannot power on. Open the chassis carefully look at the motherboard and the power of the connection is not unusual, the power switch is also not seen in the short circuit signs, conveniently attached to other accessories of the attachment tight, again boot failure.

Due to the power of the "suspect" the largest, so decided to use the replacement method to verify, just on hand has a 250W power supply, after the change, the computer is still "silent"; Is this 250W power supply is also "Li Ghost"? It was then that I noticed four IDE devices installed in the chassis: two hard drives and two optical drives. Friend said is just upgraded, it seems very likely to be the power supply exceeded the cause, I immediately unplug two of them power plug, try to boot again, the computer is still not the slightest reaction.

Just ready to give up, the computer's power supply fan suddenly turned up, and then heard the hard drive self-test, the monitor has slowly become bright, the computer started! But in a moment, start interrupted, display "CMOS Load failure", and prompted to press the "F2" key to continue to boot, press "Del" into the BIOS settings. Regardless of it, first press the F2 key, let the system continue to boot, but in any case can not enter the Windows XP desktop, had to reboot.

This time, press the "Del" key to enter the BIOS settings, the friend is trying to enter the password, but entered directly, and in the view found that the system time positioning in the January 1, 1999 0 o'clock, it is obvious that the CMOS battery is dead. Immediately bought a new battery into which, and then all the equipment on the boot, the computer successfully started, but still show "CMOS load Failure", had to enter the BIOS settings select "Load BIOS SAFE DEFAULTS" and restart, this time smoothly into the windows XP desktop, everything back to the same. In the thought that the problem has been resolved, the friend suddenly found the floppy drive icon disappeared, the system did not recognize the floppy drive! began to think that may have touched loose the floppy drive line, so reluctantly open the chassis tight, but the boot still cannot see the floppy drive. Calm down, think back to just the operation "Load BIOS SAFE DEFAULTS", is not the default to the floppy drive set to "None", restart into the BIOS settings, sure enough to prove my idea, immediately changed back, the floppy drive again can be used.

Looking back at the whole process, everything is a small CMOS battery trouble, it seems that analysis can not blindly follow the experience, but should be adaptable, according to the specific circumstances to deal with; As for why CMOS has no power, the computer suddenly can start, my analysis may be even though the computer did not start after the power, But the power supply has been powered to the motherboard, allowing the motherboard to charge the CMOS battery, when the battery is enough to enable the computer to start, it happened in front of the scene.