After the initial boot of the computer, information about a malfunction of its hardware can be displayed in the form of messages on the monitor, sound signals from the speaker, or light indications on the POST-Card. The ability to decipher audio signals will do a good job for every computer owner.
What is POST
When a computer is turned on, its central processor accesses a read-only memory (ROM), a microcircuit that stores BIOS (Basic Input / Output System) codes. BIOS provides interaction between the operating system and computer components.
BIOS launches a special self-test program - POST, which checks the computer hardware: motherboard, RAM, processor, video card, etc. The program informs about the result of the check with special sound signals. A single short “beep” indicates that the test was successful. The BIOS then transfers control of the computer to the operating system installed on it.
If, during the check, problems were found with any device, the BIOS generates a combination of short and long beeps. These combinations are not the same for different BIOS developers. The meaning of the signals can be found in the documentation for the motherboard or on the manufacturer's website.
RAM problems
If POST signals indicate problems with the RAM, disconnect the system unit from the network, remove the side panel of the case and carefully remove the RAM modules from the slots (to do this, pull down the plastic clips). Wipe the contact pad of each module with an eraser, insert into slots and turn on the computer again. If the error persists, insert the modules one at a time to identify the faulty one.
Graphics card problems
Check if the monitor cable is firmly plugged into the video connector. If so, unplug the cable, remove the video card, wipe the contacts as described above, and firmly insert into the slot.
Keyboard error
Insert the keyboard cable more firmly into the appropriate connector (make sure not to swap the mouse and keyboard connectors if you have an old enough computer) and reboot. If that doesn't work, replace the keyboard.
Faulty motherboard
Examine the motherboard carefully for swollen or leaking capacitors. Tuck in the power and hard drive connectors.
Processor malfunction
Perhaps the reason is overheating of the processor or in non-contact with the motherboard. Thoroughly blow out the cooler installed on the processor. Remove the fan and heatsink by bending the latches. Clean any dried thermal paste from the heatsink sole and processor. Apply a small amount of fresh paste to the sole of the radiator and spread thoroughly. When installing the radiator, pay attention that there are no distortions: uneven heating of the processor will lead to its failure.
ROM checksum mismatch
Replace or flash the BIOS chip.
