1 2 Previous Next 29 Replies Latest reply: Apr 27, 2013 6:43 PM by MrKoch1900
pgoodwin Level 1 Level 1 (120 points)

Just thought I'd publish a few findings on this topic. There are a lot of threads about MBPs running hot.

 

Background - 1.83 GHz Core Duo 15" MBP. Machine has always run pretty hot, but never shut down due to an overheat. After upgrading this machine with a Hitachi Travelstar 2.5" 500GB 7200 rpm drive and another 1/2 GB of RAM, I tried doing a ime Machine backup to an external drive (500 GB 2.5" USB 5400 rpm drive plugged into a hub). It got about 5-10 minutes into the backup when the computer just shut off. The machine didn't shut off doing normal tasks, but my wife had a couple of shutdowns when she was doing some movie editing (very large files), even prior to swapping out the original 80 GB hard drive. Initially I thought the RAM was defective or the power supply, but I put the original RAM and 80 GB drive back into the computer and was able to reproduce the shut down by copying many GB of files, or running Rember (RAM test SW), and even loading OS X in from a DVD.

 

I found two very helpful pieces of software: The widget 'iStatPro" and the System pref "Fan Control"

 

I watched the temperatures during the full Time Machine backup (376 total GB).The CPU temperature would get up to 250 F on transfers of very large files (like movies) or running Rember RAM tests. Anything where sustained CPU % utilization stayed up  above 80% or more for minutes at a time. It would just completely shut down.

 

I used the Widget "Fan Control" to set the Base fan speed level to 2800 rpm, set the lower temp threshold to 110F at that speed, and set the upper threshold temp to 160F where the fan would reach 6000 rpm.

 

I sat and watched a complete 376 GB Time Machine backup run, and a few times during the process the CPU utilization went to 90+% for several minutes - the same point it shut down before. This time it topped out at a CPU temp of about 230F and squeaked through. Most of the time during the backup the temp is only about 130-135 deg F when CPU utilization is down in the 20% or less range continuously.

 

Bottom line is that this model has a very low thermal margin. Over the years as files have gotten bigger (i.e.higher resolution movies), that margin was finally exposed. The control of the temperature trip points and lower threashold speeds helped it get through.

 

What I didn't get to the bottom of though was whether or not the heat sinking of the CPU is as good as it was when it was new. I didn't dig into that, and don't know how that heat sink is designed. There was nothing visibly weird looking just looking at the board with the top keboard cover assy off. There wasn't excessive dust in the machine.


3.06 GHz iMac i3, 4 GB Ram, 500GB HD, Mac OS X (10.6.8), iPad2, 60GB iPod Photo, Hp j6480
  • 1. Re: Early 2006 MacBook Pro Over Heat Findings
    Shootist007 Level 6 Level 6 (16,640 points)

    You need to clean that system out. Clean out the dust from the fans. That is why it is overheating.

  • 2. Re: Early 2006 MacBook Pro Over Heat Findings
    OGELTHORPE Level 7 Level 7 (25,815 points)

    In addition to the cleaning suggested by Shootist007, you may consider a cooling pad by your MBP, especially when you use the CPU intensive tasks.

     

    Ciao.

     

    PS:  Opening your MBP is a bit tricky but within the realm of a person of average mechanical ability.  Look at the HDD installation videos on the OWC website for non-Unibody MBPs like yours.  They will show you exactly what to do and in the proper sequence.  The most important thing to remeber is that there is a ribbon cable atteched to the keyboard and the mother board and to detach it properly before separating it from the bottom case.

  • 3. Re: Early 2006 MacBook Pro Over Heat Findings
    pgoodwin Level 1 Level 1 (120 points)

    Hi Shootlist. I did dust it out the last time I had it open. It really wasn't too bad. There was a little dust on the fan blades but overall it was pretty clean inside. I tightened all the screws inside that I could get to, as over the years the temperature cycling, they had relaxed a little. That helped the temperatures a little...like 5 deg F or so.

     

    The paper air filters look pretty clean. There's a screw on the plate holding them but when I removed it, I couldn't get the filter out. The small plate the filters are attached to look like they're pressed into a larger plate. I suppose the filters may be partially filled with micro particles and may be restricting flow a little, but again, they looked completely white, not discolored at all.

  • 4. Re: Early 2006 MacBook Pro Over Heat Findings
    pgoodwin Level 1 Level 1 (120 points)

    Hi OgelThorpe. I've had the thing apart quite a few times....I put in a new hard drive.  I've been looking into the cooling pads recently. 

     

    The thing actually runs fairly cool most of the time. Once it's stabilized and just idling, the CPU temp is only about 115 F to 120F with the case temp stabilized at 90F or so. Electronics being 20-30 F above board temperatures is fairly normal. When at extended high % CPU activity, the temperature rises fairly quickly. It got up to 230 F after the CPU was at 85-95% for about 3 minutes or so. I would think that the time to get to the hottest temperature would be a little longer than that if there was a good mechanical and thermal path from the CPU to the metal case. Tightening the screws on the main board helped a little-a few degrees. It's almost as if whatever heat sink the CPU has is not what it used to be. The temperature rises about as fast as devices do when they are in free air (i.e. not attached to a heat sink).

     

    Before retiring I designed jet engine electronic controls and am pretty experienced in the thermal behavior of electronics. I need to study the CPU installation a little -not even sure exactly where it is. Perhaps there a heat sink plate that is loose that I can't see with just the keyboard top cover removed.

  • 5. Re: Early 2006 MacBook Pro Over Heat Findings
    OGELTHORPE Level 7 Level 7 (25,815 points)

    Based on your prior vocation you obviously were not intimidated by opening up your MBP.  For the average user the pre-unibody MBP would probably create some anxiety while disassembling it.  (By comparison, the current Unibodies are a snap t0o open.

     

    What I have done in the past is to place the MBP on a couple of 3/8" x 4" aluminum plates.  After a while they do become very warm to say the least.  I have not measured the temperatures inside of the MBP or of the plates.  In light of your past expertise, I would appreciate your thoughts on this.

     

    Ciao.

  • 6. Re: Early 2006 MacBook Pro Over Heat Findings
    Shootist007 Level 6 Level 6 (16,640 points)

    Why not just change out the fan. It may be that the fan is not spinning up to its full speed when the system starts to get hot.

     

    And while you're at it take the heatsink off and put some Arctic Silver on it.

  • 7. Re: Early 2006 MacBook Pro Over Heat Findings
    pgoodwin Level 1 Level 1 (120 points)

    The more mass you have underneath that is cooler than inside the machine, the better off you are. The problem with the aluminum plates is even though they are pretty flat, they're probably only actually making good contact in 50% of their area, which means they're not real efficient as heat sinks. But the fact that they are getting warm tells you they are doing some good. I experimented with getting the MBP up off the surface in a similar fashion- haha I used a couple of post it notes pads just to allow more air space underneath, but it didn't reduce the temperature at all because there's no air flow underneath the thing.mYour plates are better because they provide more cold mass for heat to flow into. The more cold mass you put under there the better.

     

    Also haha about being intimidated taking that thing apart. My biggest fear was losing one or more of those tiny screws by dropping them on the rug...which I did. My wife and I crawled around on our hands and knees looking for it. Every time I'd pick one up, I'd tell myself.. Don't drop it. And that was just enough thinking about it to make it happen.

  • 8. Re: Early 2006 MacBook Pro Over Heat Findings
    pgoodwin Level 1 Level 1 (120 points)

    I have a widget called iStatPro which is pretty cool. It tells you about 7 different temperatures inside, and gives you the speeds of both fans. And the system pref called Fan Control is great too. You can adjust the speeds such that they run faster at the cooler temperatures than the stock settings. You can also adjust the high end temperature down so that the fans are at max speed at a lower temperature than the stock settings. The penalty for all that is fan noise though. At 6000 rpm, those little fan blades make quite a whoosh. I fiddled around with the settings until Inhad a good balance between being fairly quiet when it was idling, and only going to full speed when it was really getting very hot.

     

    I've been searching the Internet trying to find some info on the circuit board and the CPU location. If it's just soldered onto the logic board, the only way the heat gets out of it is thru the leads of the device and into the copper runs on the circuit board. Then the heat has to travel from there to a cold spot where the board mounts to the chassis. I don't know if it has any kind of heat sink on the COU or not. I didn't see a chip big enough on the top side of the board to be the CPU. I suspect it's on the bottom side of the board facing the cavity where the fan air blows past it....I just didn't have the wear withal to take that board out of there and look at it.

     

    At least I know now though that if I'm going to be doing some really long stretches of high %CPU, it'll make it thru that if it only lasts a few minutes. Like I said, above, when it's idling or only copying small files that last only seconds, it stays pretty cool-cooler than it ran before because I set the minimum fan speed up to 2800 rpm from the stock 1500 rpm. And the temperature stays about 20 deg F cooler than it used to.

  • 9. Re: Early 2006 MacBook Pro Over Heat Findings
    OGELTHORPE Level 7 Level 7 (25,815 points)

    It seems we both suffer from chronic fingerfumbleitis.  My solution when I perform internal surgery or transplants on the MBP is to place it on a towel.  This protects the cover and when I invariably drop a fastener, it lands on the towel and does not bounce on the floor.  This reduces search time enormously.

     

    Ciao.

  • 10. Re: Early 2006 MacBook Pro Over Heat Findings
    pgoodwin Level 1 Level 1 (120 points)

    Yeah. The towel has saved my butt too. I still managed to get one on the floor last time 'cause like an idiot, I pulled the MBP over to the edge of the table.

  • 11. Re: Early 2006 MacBook Pro Over Heat Findings
    pgoodwin Level 1 Level 1 (120 points)

    I found a couple of good resources while searching- links below. I'm quite sure that the thermal paste on the CPU or the Logic Board - to - heat sink paste has dried out some and no longer making good contact.

     

    Take a look at pages 104 and 106 of the service manual:  http://www.ifixit.com/Device/MacBook_Pro_15%22_Core_Duo_Model_A1150

     

    Another good assembly and dissasembly resource:

    http://www.ifixit.com/Device/MacBook_Pro_15%22_Core_Duo_Model_A1150

     

    Taking the logic board out and back in one of these monsters is no small task - many opportunities to screw something up, multiple screw lengths, lots of connections and other little assemblies to take out and put back in.

  • 13. Re: Early 2006 MacBook Pro Over Heat Findings
    Shootist007 Level 6 Level 6 (16,640 points)

    pgoodwin wrote:

     

     

    Taking the logic board out and back in one of these monsters is no small task - many opportunities to screw something up, multiple screw lengths, lots of connections and other little assemblies to take out and put back in.

    Yes if you think of it that way it can be overwhelming.

     

    But if you look at it as "It is just a bunch of screws and wires to disconnect and reconnect" it lowers the dificulty factor.

     

    It's not like you are removing parts from the PCB.

  • 14. Re: Early 2006 MacBook Pro Over Heat Findings
    pgoodwin Level 1 Level 1 (120 points)

    And slowly but surely wins the race

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