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Miscellaneous => The Orphanage => Topic started by: Magnum on March 05, 2014, 06:02:45 AM

Title: Cpu cooling fan
Post by: Magnum on March 05, 2014, 06:02:45 AM
The cpu cooling fan went out on my desktop system.

I am sure glad that it told me and shut down the system instead of letting the cpu get fried.

I am having problems finding a replacement.

It is a CE AUB0812HH 12 V 3.2 amp.

Is it specific for the CPU which is a AMD 64 ?

I had another fan, but it only has 2 wires instead of the 3 that the bad fan has.

I found the fan.

Can I just re-attach or should I put on some new cpu cooling paste ?

Thanks.
Title: Re: Cpu cooling fan
Post by: dedndave on March 05, 2014, 10:16:00 PM
hopefully, you haven't gotten the old stuff dirty (or wiped it away)

the thermal grease provides good thermal conductivity
if there are air gaps (spots where there is no grease), then you have a problem
the grease should cover the entire area of both surfaces, smoothly

as long as you can do that, the old stuff is probably ok
Title: Re: Cpu cooling fan
Post by: Magnum on March 08, 2014, 04:37:49 AM
I got the wrong fan. It is one for cooling the computer chassis.

The new one has a 4 wire connector while the old is 3 wire.

Can I use the new one in place of the 3 wire fan ?

New fan does draws twice the amperage of the old, so I quess it would be louder.

Andy
Title: Re: Cpu cooling fan
Post by: dedndave on March 08, 2014, 11:00:26 PM
it can probably be used - but you'd have to know how the different fans are wired
these extra wires are generally used to measure fan RPM
the fan wiring has to match the circuitry
Title: Re: Cpu cooling fan
Post by: KeepingRealBusy on March 09, 2014, 02:40:51 AM
Dave,

Shouldn't he also be concerned about the current draw, and not just the "extra noise"?

Dave.
Title: Re: Cpu cooling fan
Post by: dedndave on March 09, 2014, 04:26:15 AM
well - it's hard to say, really
i don't know the conditions under which the current was measured

most of these desktop fans are designed to run in variable-speed circuits
the harder the CPU runs - the higher speed the fan runs - something like that
the concept varies - some CPU's don't have temperature capability, some do

some of the extra wires measure fan speed
who knows - some fans may even have temperature sensors
the chassis fan on my desktop has 5 wires   :redface:
Title: Re: Cpu cooling fan
Post by: Magnum on March 09, 2014, 06:28:51 AM

< You don't have to use the fourth pin.  That is
< the RPM control used for very slow operation.

I disconnected CPU before testing the fan.

It worked fine.

Andy
Title: Re: Cpu cooling fan
Post by: dedndave on March 09, 2014, 11:35:28 AM
best advice i have...
get the right part if possible   :t

no reason to fry a transistor on the motherboard
Title: Re: Cpu cooling fan
Post by: Magnum on March 09, 2014, 05:01:02 PM
4 wire fan was designed to be backward compatible.

Fourth wire is not necessary for proper operation. (It's a low speed signal.)

Andy