1.The motherboard BIOS is damaged
Motherboard BIOS, the hardware store important data, while the motherboard BIOS is part of the more vulnerable, easily damaged, once damaged it will cause the system can not run.
Such failures usually occur because of the motherboard BIOS damage caused by CIH virus. General Dell Inspiron E1505 BIOS after the destruction by the virus, hard drive data will be lost, you can detect the hard disk the data is intact, in order to determine whether the BIOS is damaged; in a DEBUG card, he may be light through the BIOS on the card to determine whether the light . When the BIOS, BOOT block has not been destroyed, the display does not light after startup, PC speakers have an alarm beep; If BOOT is damaged, then power, the power and hard disk light is on, CPU fan speed, but does not start, this Can only be rewritten by the programmer BIOS.
You can also plug in ISA card, see if there is Dell E1505 displayed (if prompted, can prompt steps below.), if not the boot screen, you can automatically update your BIOS to do a floppy disk, reload the BIOS, but there The motherboard BIOS is damaged, the floppy drive did not work, then proposed to find service providers, encoder used to write the BIOS update file to write BIOS.
2. CMOS battery problem
Press the Dell Inspiron 1420 power switch, hard drive and power lights, CPU fan speed, but the host does not start. When the Dell Inspiron 1420 Battery removed, to be able to start normally.
3. Board automatic protection lock
Some motherboard with automatic detection protection, when the supply voltage is abnormal, or CPU overclocking, adjusting the voltage is too high occurs, automatically locks stop working. Performance is the motherboard does not start when the CMOS discharge can be combined with electric start, some motherboards need to open the board the power, press and hold RESET button to unlock.
4. Board temperature control disorders, resulting in Dell Inspiron 6000 no display power
Fault: temperature control on the Dell Inspiron 6000 motherboard connected line off, out on the motherboard, the motherboard automatically lead to protection of the state, refused to power. Now that CPU heat is very large, many motherboards offer a strict temperature control and protection devices. General CPU temperature is too high, or the motherboard temperature monitoring system fails, the motherboard will automatically enter the protected status. Refused to power up, or alarm.
Approach: re-connecting the temperature control cable, and then boot. Note that if your motherboard does not start or alarm, you should first check the motherboard temperature monitoring device is normal.
Related:Part one: why boot failure with no display