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Fans are spinning fast, screen is black, and pc will not boot up

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HP Compaq Pro 6305 SFF
Microsoft Windows 7 (64-bit)

PC starts up LED and fans when pressed the ON key, then after around half a min, the fan starts spinning at full speed. There is no display on monitor, I tried changing RAM, resetting capacitors by holding the power key for more than 15 seconds, removed the CMOS battery and kept for 30 seconds to restore BIOS settings but nothing worked till now. The fan spins like its high on coke...

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Make sure you physically unplug the pc when you pull the cmos battery. wait for the green light on mobo to turn off.  If nothing Try again with your monitor plugged into integrated VGA this time.

I have a 6305 MT with an A6. I’ve encountered this quirk  a few times myself. I’ve read online that cpu overheat is usually what produces this situation, but it has also happened to me after hibernation or after the restart during windows 10 updates. What happened before this occurred? 


removing the cmos battery has worked for me every time this fan thing happens.
 the last time this happened to me the cpu had crashed mid operation. I was running it 100% for some hours. Wouldn’t reboot and doing the fan thing. The cpu did feel hot and i put it near the window while I did the cmos routine. It did not work the first time. Cpu cooled basically to room temp before it came back. I checked the thermal and the fan idle speed was near zero, which would support the theory that my cpu was over heating. Worth a check!


I don’t work or affiliate with HP,  just like to offer help from experience when I can. Curious If this helps you. 


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