Replacing Fan

I have a hp XL766 and can not get it to work. Recently I restarted my computer and get a message upon startup stating that there is a ventilator fan failure and that I should turn computer off and check conector in order to not overheat. I opened the tower and restarted. I noticed the main fan was not running and thought that would be the problem. I went out and purchased a new fan (80mm Thermal Control Case Fan) and installed it. I still get the same message at start up. I have checked and know the new fan is turning. The old fan is a DC Brushless model ASB0812HH. The new fan is a DC Brushless model PL80D12M. The new fan is the same size as the old and has the same plug in to connect it to the motherboard. Any help would be very much appreciated!!!!

 

Well, only thing i can think of is make sure that the fan header plug is clicked into the header on the motherboard, and that the fan is secured onto the heatsink properly.

Usually what causes that kind of message is that the yellow cable on the fan header isnt plugged in correctly, and so it detects a fan speed of 0RPM and so thinkgs the fan isnt running.

Either that, or there is a thermal diode which is giving a reading to make the machine show that message.

You need to get a CPU fan, rather than a case fan really, because they are optimised to be mounted on heatsinks, and have the correct speed reading device on it. Does the new fan have 3 cables coming from it?

You say "Main Fan" but that message will be from the CPU fan, which is mounted on a heatsink attached to the motherboard.

 

Thanks Goldfish...yes the fan has three wires. I have tried unplugging in from the motherboard and replugging it in to ensure a good connection. Still the same thing. As far as I can tell, I only have two fans in this tower, the one in question which blows down on the motherboard and another fan that is in the power supply box. I am certainly not a computer guru but I am assuming that this fan in question is blowing cool air on the processor.?. Now what do you think? Did I buy the wrong fan? It fits and has the same connection. Thanks!

 

goldfish....

what is the heat sink you speak of?

when i referred to the main fan, i am referring to the only fan (excluding the power supply fan).

thanks!

 

The picture below shows a heatsink and the fan. The heatsink usually copper or aluminun draws heat away from the processor and then the fan cools it off.



cooked

 

That sounds about right. Most "big box" pcs only have a heatsink and fan for cooling the system, (not including the power supply fan that is).

My reasoning is that the case fan will not give a speed reading through the third cable, which the CPU fan would, and so the motherboard has no way of telling if the fan is actually spinning or not, thus why it shuts down.

A heatsink as OverCooked says sits on top of the processor, and conducts heat away from the processor through a thermal interface between the two (made with a thermal compound like Arctic Silver). The fan then cools the surface of the heatsink, so the heat is conducted away by the air. In older machines the fan was not vital, but modern machines run a lot hotter a lot faster.

 

Thanks goldfish and cooked! I will pick up a CPU fan today and give that a try. I am sure that is the problem. I will report back tonight. Thanks!!!

 

It works...CPU fan was what i needed! Thanks for all the help!!!