HELP - NX9420 GPU heat problem

[greenchili1993]

I have an NX9420 that has suddenly developed a temperature issue with the GPU. It used to run in the high 40s to low 50s. It has now started running in the 60s to 70s.  The fan is working correctly - the CPU temperature remains completely normal.

I have openned up the laptop and completely cleaned out the fan and GPU heatsink (they were very clean). Cleaning did not help. I then thought that maybe the thermal pad/grease might be drying out so I removed the GPU heatsink and completely cleaned all mating surface. I put new Artic Silver on the GPU and buttoned everything up. This made no difference either.

I'm now completely stumped and open to suggestions. The only thing I think is either the video card is going bad (its an x1600) or maybe the GPU heatsink heatpipe isn't working correctly. Or maybe the sensing diode is reporting a wrong temp? At this point I'll take every suggestion I can get. Thanks all.

[sorigen]

Hello, I think I have the same problem. I cleaned the whole cooling system and changed the thermal compound.

How did you managed to see the GPU temperature?

[il_pier]

Hi!

I have the same problem, my nx9420 shuts down because of high GPU temperature.

I wrote a post on "Lookup Freezes & Hangs" about it.

http://h30434.www3.hp.com/t5/Lockups-Freezes-Hangs/nx9420-heat-problem/td-p/271855

I replaced the thermal compound over the GPU, but the problem still persist.

In your posts you confirm that there should be thermal compound over the GPU, not a thermic pad as I supposed (I supposed that thermal compound was placed instead of thermal pad during assistance service for lcd replacing).

So the problem should be due to the heat pipe. On a working nx9420 heat pipe burns also near the fan; mine heat pipe burns only near the GPU and is moderately hot near the fan. The heat pipe seems not to work and the moderately hot temp should be due to the copper's thermal conductivity, not to the heat pipe work.

So I'm going to buy a new thermal module (p/n 409950-001) and I hope this will solve the problem.

Try 3d test and see if your computer shuts down (30 days trial)

http://www.passmark.com/products/pt.htm

Try this one to see your gpu temperature (speedfan)

http://www.almico.com/sfdownload.php

Mine GPU temp rises up to 80-90 °C and never goes down, when it reaches 100°C computer turns off.

[greenchili1993]

To Both:

I'm glad I'm not the only one with the problem. The program I'm using to get the GPU temps isCPUID's Hardware monitor (http://www.cpuid.com/). Since the fan controls both the CPU temp and the GPU temp, all I can assume is either the heatpipe is bad or the temp sensor is bad. Since I can't replace the temp sensor, I will replace the heatpipe and see if that solve the problem.  I'll report back and let you know.

[zombiefrog]

I'm having exactly the same issue, thought it was the fan initially being blocked etc, then the cpu, having touched the thermal module above the GPU its obvious why the fan is at such a high RPM. Agree with all above the copper does not seem to be doing it's job as it's almost impossible to touch as its so hot above the GPU however towards the fan assembly it is quite cool. Thank fully I have another nx9420 which I can borrow the thermal module from to see if it works.

[slarus]

Hi guys, the same problem with nx9420 - has anyone tried replacing the heat pipe unit? Several people told that they would try and no replies yet...Mine works on 66-68C (desktop, no programs running), and reaches 98C  when 3dmark2003  is running. After a while shuts down. Nice and clean inside, new thermal compound... Any suggestions?

[tib123]

The heat sink on the graphics processor IS the problem.  I have replaced the heat sink on two nx9420's. It completely solves the issue with the GPU over heating. I have five of these systems and four of the five over heat. I just ordered two more GPU heat sinks to replace the other two that are bad.  I have been banging my head on this for SO LONG! (cleanings, BIOS updates, Graphics drivers, re-thermal pasting....you name it) I also sent one in to HP when under warranty. They couldn't fix it. They just replaced the mother board & graphics card. It was the heat sink all along.
Reference this interesting article: http://en.wikipedia.org/wiki/Heat_pipe

[Nightowl4272]

@tib123   -   Hello, I'm having the same problem as everyone else here and I agree, the heat is not being transfered along the pipe to where the fan can cool it. My fan is blowing at full speed but it's cool air. I pulled the keyboard up, turned the nx9420 on and physically touched (carefully) the heat pipe. It's blazing hot near the GPU heatsink but about halfway to the fan area, it's perfectly cool to the touch. So the heatsink is doing it's job but the heatpipe isn't right?

So I'm going to replace the entire heatsink/heatpipe assembly since it looks like it doesn't come apart anyway. But I have a couple questions and a request.

Question 1 - Where did you get your replacement heatsink assembly? I've Googled part 409950-001and the only dealers I've found seem to be a bit shady. And most offer only refurbished parts which I'm leery of in this case. HP's quality control seems to be lacking when it comes to this particular part and I'm afraid the refub part may have the same issue.

Question 2 - Did it come with thermal pads and if so, did you use them or did you instead use Arctic silver or some other compound?

And my request is, since you've sucsessfuly done the repair, could you provide any tips for anyone about to do the repair (like me) to let them know what to look out for? For instance, The manual only instructs you to remove the keyboard and the fan assembly in order to gain access to the Heatsink Assembly. But once you pull the keyboard up, it really looks as though you will have to remove the Switch Cover and the LED Board to get to it. Honestly, the job doesn't look all that hard but, since you've done the job, are any other pitfalls that you think I might need to look out for?

Thanks big time for your diagnosis of this very annoying problem...HP couldn't even figure it out!  Where would we be without the internet?!

Tai

[il_pier]

Hi all,

changing the heatpipe completely solved my problem. Now it's completely different notebook! :robothappy:

You can do the work by yourself if the notebook is not still covered by warranty.

You can find the spare part you need in a hp parts store near you: http://h20141.www2.hp.com/hpparts/CountryChoice.aspx

Good luck you all.

[tib123]

Answer to question #1:  I got my heat sink here. 

http://www.hexparts.com/HP-Compaq-nw9440-nx9420-Heatsink-409950-001_p_938.html

If the heat sink was a refurb, I sure couldn't tell it.

Answer to question #2:  The new heat sink came with all new heat pads and thermal paste already in place. I installed it as it came.

Here is a link to HP videos to help disassemble your nx9420. You'll want to watch the Keyboard, LED switch cover, Button board and the Fan removal videos.

http://h20464.www2.hp.com/resultsCSR.htm?prodSeriesId=1839153&MEID=3EB1765E-CCB6-45C1-829A-17C44A106...

The one thing they don't mention or show, in the videos, is that the keyboard right hand side is double sided taped to the metal DVD shield. The tape is pretty sticky stuff and will have you thinking you forgot to remove a screw.  After I got the keyboards off the systems I worked on, I removed the double sided tape. It has no effect on the system with it gone.

I believe taking the laptop apart to this point is going to have to be a regular event. The fins getting clogged with dust on the GPU heatsink is what ruins the heat pipe in the first place.....that's what I think.  So I plan to make it an annual PM to remove the fan and clean the gpu and cpu heat sink fins.  Good luck.