System turn On,but shuts down in few minutes or in few seconds.These is due to issue with CPU overheating.
The system shuts down to save further damage to the board.
The CPU needs certain voltages to perform.Every CPU needs different voltage as per the system motherboard.
The required voltage should no exceed or decrease as per required voltages.
To what voltage is required for CPU.Search on the CPU manufacturer website.
For example in case of intel brand CPU.You can search the CPU details on ark.intel.com website.
In case of Intel CPU go to these website and insert the CPU number mentioned on it and you will get complete detail about that particular CPU.
In that details see what voltages are required by CPU.
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REASONS FOR CPU OVERHEATING:----
REASON 1) Faulty PWM chip.
Solution 1) PWM chip drives high gate signal to high side mosfet. Due to these the Supplied VID core voltage to CPU exceeds then required voltage.
For example if CPU needs 1.5 volt to operate and PWM chip is supplying more then 1.5 volt then CPU will overheat and system will shut down,when comes to certain saturation level.
So test PWM channel voltages.If its found excess,then replace PWM chip.
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REASON 2) Faulty CPU Fan or dirty HEAT SINK.
Solution 2) If CPU fan is not running at all,then try with another working CPU fan and see if its running.If the new CPU fan is also not running then its problem with CPU fan connector.You will have to jumper the +5 volts to CPU fan connector by other +5 volt port on motherboard.But CPU fan connector getting faulty is very very rare chance.Its near to nil possibility of CPU connector getting faulty.On most of cases its either faulty CPU fan or not connected properly CPU fan Connector on motherboard.
But if CPU fan is running but its very slow to run,then replace CPU fan.Because CPU fan is not running properly or not running At all the CPU heats and then shuts OFF the system.
On some cases the CPU fan is not the issue but problem is related to dust getting clogged and collected into rails of CPU fan Heatsink .Just clean the heat sink with soft brush and see,that will help.
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REASON 3) No thermal paste on CPU.
Solution 3) Thermal paste is the cooling agent type paste.It never lets the chips to get overheated.Please dont exceed the thermal paste.It should be applied in limit.If you exceed the thermal paste and if the paste is having inductance,then it can short the circuit board.Just check if there is thermal paste applied properly on top side of CPU processor.Handle processor very carefully.Its costly part and also very delicate.Apply thermal paste on top of Process ,if the old paste is totally vanished or very dried.Then let the new thermal paste get dried for few minutes.Then place CPU fan assembly on CPU socket.Connect its Fan connector to board and see if CPU still overheats.
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REASON 4) FAULTY CPU.
Solution 4) Its very rare CPU getting faulty.But dont ignore these troubleshooting step.On some cases,when nothing is helping,then issue is with faulty CPU.Try with another spare working CPU.If the system runs with another CPU and that too without getting overheated then problem was previous old CPU.
Please note:--- Any CPU will not work on Any motherboard.Every CPU and Every motherboard has its compatibility.You have to first confirm that these CPU is compatible with these motherboard.These you can confirm on CPU manufacturers site or you can get help from other hardware engineers.
If you use Non-compatible CPU on your motherboard,then working CPU will not Support on your motherboard.
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In case of CPU overheating Problem.Once you confirm these possibilities.You will mostly trace out the problem.It can be any one of these possibility causing CPU overheating.These basics will help you.
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If there are any other possibility that can cause CPU overheating,then please don't hesitate to share your views here to these article.These will help others who follow these article,for troubleshooting CPU overheating problem.
More suggested help links :--------------
Troubleshoot Dead Motherboard
Troubleshooting NO Display
Problem on Motherboard
http://technoanswers.blogspot.com/2012/10/troubleshooting-no-display-problem-on.html
