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DL380 Fans - What does what and what controls PWM?

ajthemacboy
Occasional Advisor

DL380 Fans - What does what and what controls PWM?

Hey everyone. I have an old HP Proliant Dl380 G3 (yes I know, I should probably just buy a new one) that, upon startup, says "Fan 7 not present, fan solution not sufficient."

 

Everyone says this happens with old servers, and if I can't fix this problem I will buy a new server, but I'd like to at least try to fix this one. 

 

I have replaced the fans and done everything I can to try to fix the problem without replacing the system board. I have dissasembled and cleaned the whole system with no luck.

 

I had the idea that I could possibly jury rig the fan connection to trick the system into thinking the fan is working, so I dissasembled a spare fan and was surprised by what I saw.

 

Here are the pictures: http://imgur.com/a/CaQqB

 

I cannot find any documentation about what wires control what in the system.  

 

You will notice that there are only 3 wires (red, yellow, and black) going to the fan itself. One wire (black) loops around on itself and goes back out the port. The other two (yellow #2 and green) go to the LED. 

 

I know enough about fans to know that you can't have a PWM signal on only 3 wires. I also know that the fan spins when the server stars up, but I've read that this problem can be caused by having low fan speeds. I read on one post that someone used a shopvac to blow into the fan to trick the PWM into going high, and the system booted fine. Unforutunately I cannot find that post at the moment or I would show it to you. 

 

What I need to know is, is there ANY possible way I could trick the system into booting?

 

Please note: I understand I run the risk of damaging the server by doing this, but I'm not going to spend $40 on a new system board when I can buy a newer and better one for slightly more, so I might as well try to fix it and have it break then to do nothing with it.

2 REPLIES

Re: DL380 Fans - What does what and what controls PWM?

 

Hi,

 

Fan 7 is for the power supply and processor zone.  It may be that the processor might need a fresh coating of thermal paste! (I am trying to make a guess here not completely sure). Reseat the power supply  or try swapping it.

 

Documentation about internal fan wirings are not available at the HP Support portal.

 

Regards,

 

Vijayasarathy

I work for HPE
Views expressed herein are my personal opinion and is not the views of HPE
To say thanks click the white "thumbs up" icon below!!!
ajthemacboy
Occasional Advisor

Re: DL380 Fans - What does what and what controls PWM?

Hi, thanks, I'll try that, but wouldn't 5 and 6 be for the processor zone? Fan 7 would only get to the power supply.

 

Judging by this post:

http://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c00348309-9

 

If the processor were overheating, the system would suspend for 5 minutes and then shut down. Mine suspends immediately after:

 

2 beeps

 

2 beeps + 2 long beeps + 2 beeps