On Cpu fan connector with 4 pins the voltage description are as mentioned below.
These details will help.
Thanks.
The Cpu fan connector pin voltages are as follows:-----
See the image shown below:-----
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These details will help.
Thanks.
For more help go through these help links:----
Troubleshoot Dead Motherboard
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Troubleshooting CPU Overheating Problem on Motherboard
http://technoanswers.blogspot.com/2012/10/troubleshooting-cpu-overheating-problem.html