Repairing or Resetting the PC System
PC Check Through System Diagnostics
To check the condition of the hardware on your computer needs to be diagnosed. There are three types of diagnostics on computers, namely:
POST (Power-On Self-Test)
• General diagnosis (routine)
• Diagnosis seeks and solves defects
Every time the computer is turned on, it will automatically start with a diagnostic step known as POST. This POST will check and test all system components. If a problem occurs during POST, a message will be delivered to the user. With very varied manufacturers of motherboards and BIOS ROMs, the beep codes that are given also vary, meaning that for the same damage a different beep code will be given due to differences in the manufacturer of the ROM BIOS or motherboard. The all memory test is included in this POST step. The duration of the test depends on the size of the installed memory capacity. However, POST does not check all additional / expansion equipment such as printers, modems, etc.
To find or determine the type of damage that is on the PC, it is necessary to check the condition of the hardware on the computer. This examination includes POST (Power-On Self-Test), general diagnostics (routine), and diagnostics looking for and solving defects. From the results of this examination, it will be known the location of the damage and the type of damaged components and then repair the part that is experiencing the damage.
- Troubleshooting Motherboard
a). Problems that may occur
A computer system consists of motherboards, daughter boards, power supplies, floppy drives, monitors, keyboards, and several other devices connected via connectors and cables. A problem in one equipment will affect the operation of other equipment and sometimes interfere with the operating system. The following checks will help solve the problem.
• ‹Check connection of the main power supply cable and DC voltage cable.
• ‹Check the keyboard cable connection.
• ‹Check the connection of the monitor cable and monitor power cable.
• ‹Check CMOS configuration settings‹ Check the connection of the power cable and drive data cable.
After all the checks have been done, turn on the power switch and look for POST error messages. From the POST message problems can be localized and fixed. When POST cannot run, a problem occurs with the motherboard and its circuit. By checking the signal on the I / O slot, the problem of damage to the motherboard can be identified because all CPU signals are connected to the I / O slot.
- Troubleshooting power supply
A general check of the power supply function is:
- For the TX type
If the power switch is turned on, the fan will spin, the voltage on the P8 and P9 sockets when measured using a voltmeter. Especially for signal power good, if measured with a voltmeter, it will have a voltage of + 5V for a moment then it will drop to close to 0V when the power switch is turned on.
- For the ATX type
If the power switch is turned on or the power cord is plugged in, the fan is silent, all voltage in the socket, when measured using a voltmeter, will be zero, except at pin 9 it is + 5V as the voltage source in the standby position. If pin 14 is connected momentarily with pin 9 using a cable, the fan will rotate, the voltage at each socket pin is 20 when measured using a voltmeter. Especially for signal power good, if measured with a voltmeter, it will have a voltage of + 5V for a moment then it will drop to close to 0V when the power is turned on.
- Possible Damage
Total shutdown (no output voltage on all pins) Output voltage is unstable Output voltage + 12V greater Output voltage + 12V drop No output voltage + 5V No voltage signal on power good
- Procedures and troubleshooting
Check the presence of a voltage source from the grid, if not there (meaning the damage is in the voltage source / dead, repair the road / wait until it turns on), if there is, do the next check. Check the power cable and connector using a multimeter. If it is disconnected/replaced with a cable that is still good, if it is good, do the next check.