Mac Pro Problems (WIFI Dropouts, Locking up, Overheating Northbridge chip.)

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Level 1

4 points

Mac Pro Problems (WIFI Dropouts, Locking up, Overheating Northbridge chip.)

Hi guys,

I'm having some issues with my Mac Pro. Was wondering if you think it might be a software, or hardware issue? I've described the symptoms below. Does anyone have any advice? Thanks so much for your help!

- WIFI DROPOUTS: Wifi works for a few minutes then disconnects, stops seeing networks until a reboot. (Generally works for less times when rebooted quickly which leads me to think it's an overheating issue. I.E. If I was to leave the computer off for a few hours, it would last 10 minutes. If it cuts out and I immediately reboot it lasts about 30 seconds. WIFI is stable on other devices (Macbook Pro + iPhone)

- NORTHBRIDGE CHIP RUNNING EXTREMELY HIGH TEMP: Temperature Monitor was reporting 127 degrees celsius for my Northbridge Chip, overclocking my fans brought it down to about 120. I've brought the heat down by dusting out the computer and it's sitting around 113 with fans at full power.

- INTERMITTENT LOCK UPS / CRASHES: Computer's mouse will freeze up occasionally, then resume activity after a few seconds. (Causing all music / processing activity to also lock up). About 25% of these lockups result in the computer doing a hard restart automatically. (It seems like the crashes happen more often when streaming music / video. {I.E. Playing tracks on Soundcloud)

SYSTEM DETAILS:

Early 2009 Mac Pro

2 x 2.26 GHz Quad-Core Intel Xeon

ATI Radeon HD 4870 512MB

OPERATING SYSTEM: 10.8.4

Cheers,

Adam

Mac Pro, OS X Mountain Lion (10.8.4)

Posted on Jun 10, 2013 9:02 AM

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Answer 1

The hatter

Level 9

60,990 points

Jun 10, 2013 9:20 AM in response to AdamB123

why are you using a 4 yr old ATI 4870?

Run AHT off your OEM DVD

What are you using to monitor temps?

My first thought is a faulty sensor reading.

Those systems with 10.5... up thru 10.6.2 had an issue with audio and high processor temps - iTunes or anything else but the cause was they were poorly written for how Hyper-threading works and would basically overwork an idle processor thread.

SMC Reset

I would say, don't use it in this condition. Remove any changes made to RAM or additional cards, reset everything, use DATA-Vac to blow dust out of every crevice.

Every crash and freeze can corrupt the OS or the directory so take action. I would start with a clean install. If you upgraded to 10.7 or above over the old 10.6.8 then definitely go with a fresh install on a new drive. Setup Assistant makes it easy to be back running.

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Answer 2

AdamB123 Author

Level 1

4 points

Jun 10, 2013 9:38 AM in response to The hatter

The ATI 4870 came with the computer.

My original OEM DVD is long gone, and I upgraded through the app store. I've tried the shortcut (D) when booting, and it doesn't do anything. Is there any way I can still run the test?

I'm using 'Temperature Monitor':

http://www.bresink.com/osx/TemperatureMonitor.html

I figured faulty sensor reading as well, but it does seem to be affected by fan RPM, and is somewhat lower now that I've air-dusted the computer.

***

I suppose at this point it's best to figure out a way to run AHT? Is there a way of running it if I don't have the OEM DVD? It's strange that the boot command does nothing. (I've tried both a wired and wireless keyboard.)

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Answer 3

The hatter

Level 9

60,990 points

Jun 10, 2013 9:45 AM in response to AdamB123

you need the OEM DVD. Long gone and didn't file away or copy is not helpful. Only from DVD. Yes it was on the original hard drive but that always gets changed (as it should, and should be reformatted with each new OS too)

yes I know some got the BTO 4870 but its performance even compared to a 5770 - and there are better cards out now. ATI card's and their fan (any gpu really). Thought you might have it and the GT120 and to try with one or the other but not both and see if it was GPU related. Or RAM even can do odd things.

Bresink is very good at what he does. HM version has a few added features of course, like alert on and track a sensor.

If it was just a fan issue, SmcFanControl 2.4 will write a new good plist and get the fans under control.

SMC reset should have been done - but don't keep redoing.

Only new (2011 iMac and MacBook series) that shipped with Lion or later, but NOT any Mac Pro, have firwmare to support AHT over the net from Recovery Mode.

The OEM DVD from Apple is $20 or so.

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