Lets say the we have a computer that fails to Power on. What we should do to find out what is the problem? Where we must start checking?
On this guide i will show you in simple steps a typical Hardware fail resolution process.
1: The pc does not power on
First of ll open the PC side cover and check the Motherboard for any bad Capacitors.
1-1: The pc does not power and no fans are working when i press power button:
If Capacitors are Ok then we must check the PSU (Power supply), the most easy way to check power supply is to Short 2 pins of the main 24 pin power socket.
If we short out Green and one of Back power cables the PSU must start working (the fans will start spinning), if not, then the PSU is BAD.
Keep in mind that in this case you must REMOVE the power sockets from Motherboard,Graphics Card,HDD/SSD’s and from any other connected device BEFORE testing it this way.
Also, on some non-oem PSU’s the colors may defer.
1-2.The Pc does not power on but the fans are spinning and there are no beep sounds when i turn it on.
In this case, the problem may deffer, start by disconnecting all devices (Hdd,SSD,CDROM,Folppy e.t.c) and reseting bios.
To reset Bios,Disconnect power cable, remove Bios battery, press power button (with power still disconnected) 2-3 times to full discharge and reconnect power and Bios (CMOS) battery.
If that did not work, try removing one by one the RAM Memory Dimms (if you have more than one), if it’s only one RAM, try replacing (temporarly) for testing.
Still no success? Then remove and reassemble CPU, many times cpu’s may not contact well in motherboard socket. In this case, remember to clean cpu with a dry clean cloth.
If that did not give any results, then probably the problem is Motherboard.
1-3: The PC beeps when i press the power button but does not show anything.
Check the beeb sound codes, the number of beeps are the defect code.
HERE is a full list of Beep codes for almost all BIOS.
2:The Pc turns on but crashes when trying to Boot
Start by checking RAM memory, to do this Download Hirens Boot CD, burn it on a CD or USB stick and boot from it.
In the Hirens Boot Cd boot menu, go to DOS Programs> Testing Tools. There is a tool called MEMEST86+, that tool checks the RAM.
Leave it running until 100%, if you got a red screen like above then your RAM (or one of RAM Dimms) is BAD.
If you have more than one RAM Dimms, remove them one by one and repeat the memtest to find which is the bad one.
2-1: The RAM is OK but pc still Crashes when trying to Boot
Check your Hard Drive (HDD).
Once again, power up Hirens Boot CD and this time go to Dos Programs>Hard Disk Tools> HDD Regenerator
Select your Hard Drive form the list and “Test without repair” option.
This tool will check your hard drive, it may needs several hours to complete the test.
If you got Bad sectors (Red “B” symbol when testing) you can stop test since HDD needs replacement (is bad).
2-2: The HDD is OK but pc still crashing when trying to Boot.
Make a checkdisk: Many times when the pc is shut down incorrectly some files may be corrupt and the hard drive may need check-repair.
To checkdisk, boot from Hirens Boot Cd and this time load Mini Windows XP (or Mini windows 7) from Hirens Boot CD Boot menu.
After Checkdisk, we must check registry. Go to Mini XP HBCD icon on tray menu and right click to load “REG Edit PE” tool:
Once mini Xp boots up, open “My computer” and find out your hard drive letter (usually c:, open a command prompt (CMD shortcut on desktop) and type there “chkdsk /f c:” without quotes (where “c:” is Your hard drive letter).
The check disk will finish in minutes.
Open it , browse to your Windows directory and click ok on all messages except the one asking to load “ntuser.dat” for editing, on that wiondw click NO.
When RegEditPe loads click on on above mesage and close it, if you got an error when RegEditPe trys to load registry, then probably you have a corrupt registry. If RegEditPE has fixed possible errors them it will give you a message that registry has been repaired.
3:The Pc turns on but shuts down after some time
Check if your Cpu heatsink has been covered with dust and if Fans are spinning well. This is a usual problem, many times Cpu and Gpu heatsinks are beed totaly covered with dust and/or Fans are not operating well.
The pc overheats and shuts down after some time.In this case, clean the dust with a high air pression and inspect the fans.