MacBook Pro 15″ 2.6Ghz
Fans run high on boot. Even with little or no use, the fans run on full. Fans run at or near 6000rpm at rest (1000rpm would be normal at rest.)
Loose or failed temperature sensors. Logic board issue – often caused and covered by the NVIDIA logic board recall.
Have an Authorized Apple Service Provider (like MyService.com) test the logic board and see if it’s covered under the NVIDIA recall (only AASP’s have the means to test and see if the board qualifies.) Even if your MacBook Pro is out of warranty, this repair may be covered.
Contact one of our Service Advisors for more information.
MacBook Air Late 2008 2nd Generation Logic Board
The inside of a MacBook Air is just as slick as the exterior.
The logic board (pictured above) is small, clean and simple. The integrated RAM, thin heat-sink and short fan add to the low profile of the overall design.
While so far the MacBook Air logic boards have proven to be very stable, we do see quite a few liquid spills which require cleaning and repair. Replacing components on these units takes very precise workmanship. Working on the Air is definitely a tech favorite.
[ MacBook Air Repairs & Upgrades ]
Inside of an iMac G5. Temperature Sensors Highlighted.
Machine Type: iMac Intel or G5
Symptom: Fans are always running (come on more often) after a hard drive upgrade or service.
Likely Cause: Temperature sensors were not reseated properly.
The temperature sensors help tell the computer when to turn the fans on and what speed they run.
On the iMac, there are temp sensors over the optical and hard drive. If these sensors aren’t secured properly in the right position to a new drive, the readings may not be accurate causing the fans to come on when they shouldn’t.
Since the temp sensors are originally applied using sticky glue, they should be secured back into place when installing a new hard drive or optical.
We’ve seen a lot of cases of iMacs coming in with the fans always on after someone (not MyService) installed a new hard drive. The temp sensor was usually in the wrong place or had come loose inside the case.
If you’ve done a DIY upgrade, make sure to check the temp sensors first if you are experiencing any fan issues.
Heat pipe from a 15" MacBook Pro
How can you keep increasingly hot CPU and GPU chips cool while making laptops thinner?
The answer is smart cooling using a combination of heat-sinks, temperature sensors and airflow.
The Fujikura heat pipe is a good example of effective laptop cooling.
Here’s how it works:
1. The hottest components on the logic board are the CPU, GPU and Northbridge. The tops of the chips are connected via thermal grease to their contact plates (1.)
2. The heat is then carried (dissipated) via “pipes.” Inside these pipes are a spiral metal filling and fibers that “draws” the heat down the line.
3. On the pipe itself, temperature sensors (2) are placed to determine how hot the system is getting. More graphics intensive apps will produce more heat and the temperature sensor will report the temp back to the system to determine fan speed.
4. The heat is this taken to a heat-sink (3) which further spreads out the heat. A fan is connected to this heat-sink and draws the heat out of the system.
[ Fujikura ] [ Fujikura Technical Info ]
MacBook processor getting new thermal grease.
Thermal grease is a paste like substance that is used to aid a components heat transfer to a heat-sink.
In other works, thermal grease helps get the heat from a chip onto a heat-sink. The heat-sink then sends the heat to a fan or dissipates (spreads) it out.
Overheating can lead to component failure so making sure processor and graphics chips stay cool is very important. If thermal paste is not applied properly, chips can overheat and fail.
Here are a few good tips to keep in mind:
1. If you remove a heat-sink from a processor to perform a repair or upgrade, always clean the old thermal grease off (using rubbing alcohol) both the chip and the heat-sink and apply new thermal grease when re-assembling. This makes sure you have a fresh tight seal (no air pockets) and good conductivity.
2. Buy the good stuff. Different thermal greases have different heat transfer properties. Silver compounds transfer heat better and keep chips cooler than standard silicon. Cheap grease can also dry our faster and lead to higher temps. We use Arctic Silver 5.
3. Cover the surface of the chip (that makes contact to the heat-sink) but don’t apply too much. Too much thermal grease will keep the heat from getting where it needs to go (the heat-sink.) Spread the grease flat so they’ll be no air pockets.
4. Some of the higher end thermal grease contains metal which conducts electricity as well. Make sure that any excess grease is cleaned off of the logic board to avoid shorts.
FYI – Thermal grease is also commonly known as thermal paste & heat-sink compound.
A helpful (and free) OS X widget we use everyday is iStat Pro.
iStat Pro is a customizable, real time system monitor that displays info about your Mac. This dashboard like utility shows network activity, CPU & Memory usage, disk space, battery info, fan(s) speed and temp readings.
We use this utility to test fans and monitor internal temperature sensors.
Mac laptops contain many different temp sensors that help the system determine fan speed. A failed temp sensor or broken fan can lead to overheating which in turn can lead to component failure. This app is very helpful in diagnosing heat related issues.
There is also a new iStat Server and iPhone app for remote monitoring which is very helpful for server admins.
[ iStat Pro ] [ Version Tracker Download Page ]
Apple released a new SMC firmware update today for the original (non-unibody) MacBook Pros. This update further refines the fan behavior to try and keep those graphics chips cool. Highly recommended software update. Keeping your MacBook Pro running cool is the best way to keep the machine healthy.
MacBook Core Duo Fan
At this point most owners of the core duo MacBooks (1.83GHz or 2.0GHz) have probably addressed issues arising from problems with the firmware that these books were shipped with, however, we still see these problems with some regularity.
These problems could manifest as, but are not limited to, issues with backlighting, sleeping and waking for sleep, charging the battery, fans, and temperature controllers.
These problems can be fixed with Apple software update or with the EFI or SMC updater in System Utilities. The Extensible Firmware Interface (EFI) is a small program residing on a chip on the Main Logic Board that helps Mac OS communicate with the hardware. Similarly The System Management Controller (SMC) is also an integrated circuit that helps control certain functions such as the Fans that also interfaces with the Main Logic Board.
It is important to follow the on screen instructions provided for the installation of the EFI and or SMC updates, failing to do so will not properly install the firmware. In most cases this means having a working AC adaptor or a working battery.