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10.6: One possible cause of 'random sleep' in Snow Leopard

Tue, 20 Oct 2009 07:30:00 -0700

Shortly after Apple issued 10.6.1, my 2009 iMac (2.93 GHz) began to randomly sleep, sometimes quite often, sometimes with hour-long intervals in between. The kernel began logging localhost kernel [0]: Previous Sleep Cause: - 101 after each incident.

None of the three Apple sources I contacted would precisely identity this error code. There was no reference to it that I could find on the internet. The standard reply I got was that errors logged with a negative sign are abnormal, which has been documented, and that although Apple's engineers were aware of it, the exact meaning was closed-source. I was told, however, that this indicated a "partial kernel-panic."�

In each case I told them I had no idea what they were or weren't allowed to say, and I didn't care -- I was just trying to fix the problem. I tried every possible method of booting Snow Leopard in both 32-bit and 64-bit modes, but couldn't solve the problem. Oddly, I wasn't able to reproduce the same...

Use a G5 as headless port/drive extender and MIDI server

Thu, 9 Jul 2009 07:30:00 -0700

The new Macbook Unibody has about five ports. In my case, all of them are full all the time. Unless you buy a hub, why not use that defunct G5 for additional ports and devices? You may save some energy by not relying on a large number of external devices (keyboard, monitor, hard drives, etc.) or AC power. I was also tired of the issues with a USB powered Oxygen 8 keyboard from M-Audio. Using my G5, the VNC access is actually somewhat tolerable for light operations at reasonable resolutions. If you have your Mac configured with a SATA II card and an internal drive mounting system, you can have access to more drives at decent speeds.

These instructions cover setting up a FireWire 800 link, a MIDI Network Link, VNC access using Vine Server, which is much faster than ARD. Also, you can easily use your G5 as a bridge to connect to two-pin devices (most video-cameras). Latency is minimal and the data path is more than sufficient, if all other interfaces are disabled it is also so...

New logic board for older G5 iMacs with bad capacitors

Tue, 17 Mar 2009 07:30:01 -0700

Not so much a hint, but a suggestion which hopefully will help someone else. My iMac G5 (1.8 GHz, 2005 model) started having frequent kernel panics which I quickly realized was hardware related, as it persisted when booted from an external drive. When I opened the machine, I saw the dreaded bulging capacitors.

This was a known issue with a defect in the manufacturing of these capacitors, and Apple had a program to replace the motherboards when the capacitors failed. As I learned when I called the Apple rep, the program just ended in January and there was "nothing to be done." As I explained to the rep, I was being penalized for my machine lasting a bit longer than others, which made no sense. In fact, since there was no recall issued, I couldn't get my machine repaired before it failed, so Apple really had no choice in my opinion but to...

Possibly recover from a dual CPU failure on a Mac Pro

Tue, 26 Aug 2008 07:30:00 -0700

When I tried to boot my Mac Pro recently, it failed -- all I got was a black screen and a chime. I opened the case, and on the motherboard, I saw two LEDs were red: the cpuA and cpuB failure lights.

My warranty is over, but here are the steps I followed to get it working again:

Turn off your Mac and unplug the power cord.
Remove the CMOS battery on the motherboard (just above the graphic card).
Wait 10 seconds -- I'm not sure if this is necessary, but it worked for me.
Plug the power cord back into the Mac.
Press the power button. The Mac should boot normally and give you the startup chime, but you want your CMOS battery back.
Turn off the Mac, then unplug the power cord again.
Put the CMOS battery back in.

That's it; boot and enjoy!

[robg adds: I've never seen this on my Mac Pro, and I'm not sure if it's a sign of a failing CMOS battery, or something else. I'm publishing the hint beca...

How to pull stuck hard drive sleds from the Mac Pro

Thu, 22 May 2008 07:30:00 -0700

I've been swapping hard drives in my Mac Pro a lot lately, and they kept getting more and more difficult to pull out once they'd been soundly seated, to the point where I was in danger of bending the lip of the sled.

I was about to experiment with lubricating the things with a little graphite or similar, when I discovered that they slide out much more easily if you reach both hands inside the Mac and pull gently and evenly on the far edge of the drive itself.

Free up a spare drive sled in the Mac Pro

Mon, 19 May 2008 07:30:00 -0700

Need an extra MacPro hard drive sled for swapping secondary hard drives? If you do not need to swap out your primary hard drive, take it off of the sled and carefully install it permanently into the first slot without the sled. First put some thick felt on top of the grey fan box. The hard drive is supported by the grey box and felt perfectly solid in this setup. Now you have a free hard drive sled to swap drives in the other three slots -- this is better than pay $29 plus shipping.

[robg adds: While I do have a Mac Pro, I'm not going to test this hint ... I don't swap drives often enough to merit a spare sled. Looking at the interior of the machine, though, it looks as though it would work fine -- though clearly it's not the recommended drive mounting method. Proceed at your own risk...]

Possibly solve system issues after G5 video card upgrade

Tue, 19 Feb 2008 07:30:01 -0800

When I upgraded the video card on my Dual 1.8ghz PowerMac G5, I started having many difficulties, including:

Optical drive not recognized.
Video card fails to power display.
Hard drive(s) not recognized.

After several frustrating days, the solution was to reset the PMU on the motherboard. I suspect that on a newer G5, resetting the SMU would have the same effect. So, if you're out there having a hard time upgrading your G5, give it a shot!

[robg adds: I can't confirm this one -- if anyone has had a similar experience, please post.]

Recover from an incorrect resolution setting on a mini

Mon, 17 Dec 2007 07:30:03 -0800

Apple's Intel Mac Mini has only one display connection, the DVI interface. In case someone has chosen a wrong display resolution for a connected display, it is very difficult to switch back to a usable resolution.

When (for example) using a Benq LCD connected via a VGA to DVI adaptor to the Mac Mini and changing the frequency from 60Hz to 75Hz, the Mini will always remember the chosen resolution, even if a PRAM reset or complete hardware reset is done. So the screen still stays black, as 75Hz can't be shown although the Displays System Preferences pane offers this frequency. It doesn't matter if you are connecting another display to the interface and afterwards changing the resolution; the Mini keeps on switching back to the former one if the misbehaving display is re-connected.

In order to switch back to a usable resolution, you will have to remote control the Mini from another Mac using screen sharing, Apple Remote Desktop, VNC, or Timbuktu. Even though the Mini...

10.5: Enable nap mode in 10.5 on G4 MDD systems

Thu, 15 Nov 2007 07:30:02 -0800

Some G4 Mirrored Drive Door (MDD) systems have cooling systems that run loudly as the CPUs get hot, especially the model affectionately known at the "Windtunnel" G4s. On those systems, enabling nap mode brings the normal operating temperature down remarkably well, thereby quieting the fans. This was covered in this older hint.

The method is basically to install the last version of Apple's C.H.U.D. tools that allows Nap Mode on those machines, which is version 3.5.2 [21MB download]. That version still works with Leopard, although notably it misreports cache sizes. However, the old command line utility, and therefore the derived AppleScripts, that people have relied on until now to enable nap mode h...

A multiple-drive Mac Pro Migration Assistant issue

Wed, 8 Aug 2007 07:30:00 -0700

If you order a BTO Mac Pro with two internal hard drives, you may want to make a note of this. To make a long story short: Before firing up a new Mac Pro configured with two internal hard drives to run the Migration Assistant, turn it on in Target Disk Mode and rename the empty second hard drive to something other than Macintosh HD. Now, the explanation:

I was setting up a new Mac Pro for a user at one of my clients, and attempted to migrate her from her existing Power Mac G5. The new machine was configured with two internal hard drives, 500GB each. I attempted to migrate her data from the initial Setup Assistant, and everything went smoothly until we got to the actual "Transferring Information" screen -- no time estimate ever appeared in the progress bar, and the drives were not making sounds that would indicate they were being accessed.

I ended up rebooting the new machine via the power button and choosing not to migrate data when the Setup Assistant ran...

One way to 'mirror' DVI displays on a Mac mini

Tue, 27 Mar 2007 07:30:02 -0700

I am in the process of creating the "ultimate" Mac mini-based home entertainment system. One issue with using a mini is the lack of dual-monitor support, which is a real hassle if the mini is attached to a projector -- turning on the projector to see the screen each time is expensive and time-consuming. Since the mini only has one video output, I came up with a way to effectively mirror the video to both the DVI projector and a DVI-input LCD monitor:

Buy a DVI "splitter" cable (I got mine on ebay). You want a two-female to one-male DVI-D splitter.
Plug the monitor into one fork of the splitter.
Take the cable from the projector, and break off pins 6 and 7 (pinout chart). This will disable the monitor sense function, and the mini won't "know" the projector is connected. Plug it into the other fork of the splitter.
Make sure the LCD monitor's resolution matches the projector's native re...

Quieting a Mirrored Drive Door Power Mac G4

Wed, 28 Feb 2007 07:30:00 -0800

I have owned an awesome Apple Powermac G4 for about two years now. It's a Dual 1Ghz machine, which is commonly known as the Mirrored Drive Door (MDD) model due to its mirror finished optical drive doors. It has been a faithful servant so far for all sorts of stuff like video editing, music production, photos, web surfing, email and business duties, to name just a few.

I noticed when I first got it that it was a bit noisier than my old G4 533 Power Mac, but until my girlfriend's mother complained that it kept her awake all night, I didn't really take much notice of it. After that, though, it started to drive me crazy and I started a long campaign to quieten the thing down.

First thing I did was search Google for information on how to do it, and I found this page, which documents in detail how to replace the main 120mm cooling fan.

After tryin...

Improve very poor AirPort card range on G5s

Wed, 3 Jan 2007 07:30:00 -0800

This is going to be ridiculously simple for many people, but hey, I made this mistake and even Apple Support couldn't figure it out. Plus, documentation at the present time for installing AirPort cards is designed for a replacement card, which misses a vital step.

Anyway, if you have a G5 and have installed an AirPort card yourself, you should know this: Strictly speaking, there are two antennas!

There's the small internal antenna which you must click into the top of the AirPort card inside the Mac -- this bit is well documented.
Your Mac originally came with a T-shaped object, which is the external AirPort antenna designed to overcome the metal casing of your Mac. Plug this into the AirPort port on the rear of the machine, and your range will increase from about 1m to ... well, much, much more. Go look in the box -- it's probably still there!

I hope this saves someone some...

Recover apparently dead USB ports

Fri, 3 Nov 2006 07:30:00 -0800

The front USB port of my dual 2.0 gHz G5 desktop seemed to go dead. Flash drives would blink once and not mount. System profiler would show nothing in the port. A discussion on an Apple hardware forum had the solution: shut down the desktop and unplug the power cord for 30 minutes. Restart with nothing connected, then connect each USB component. I tried it and I found all the ports working again!

[kirkmc adds: You never know... I guess this has something to do with letting the capacitors somewhere inside the Mac lose their power...]

A possible fix for a broken G5 temperature sensor

Thu, 12 Oct 2006 07:30:03 -0700

While much has been written about the placement of the drive bay temperature sensor on the first generation G5 Power Mac, I was unable to find information about what to do in case of sensor failure. In my case, the drive bay sensor reported temperatures oscillating between 77 degrees and 255 degrees in less than one second!

After trying a PRAM reset, a PMU reset (my model does not have a SMU), resetting NVRAM in Open Firmware, etc. to no effect, I finally disconnected the drive bay sensor from the motherboard. I expected all nine fans to rev up to full speed, but instead my fan noise problems disappeared! Furthermore, the drive bay fan, as well as the rest of the G5's fans, still spins up in response to the remaining, functioning sensors.

As usual, all disclaimers apply -- doing this can ruin your machine, and will certainly void your warranty, and should only be done as a last resort.

10.4: Resolve Bluetooth range problem on Mac Pros

Thu, 28 Sep 2006 07:30:08 -0700

My new Mac Pro had a problem with Bluetooth: the reception between the Mac Pro and my wireless Mighty Mouse was terrible. The mouse worked fine at about two feet from the Mac Pro, but at three feet, it skipped and stuttered.

I contacted AppleCare, and they were going to send a technician to change the Bluetooth module. It turns out, in the meantime, that I found this thread on Apple's discussion boards talking about this problem, and offering a solution.

In short, there are a few wires coming from the motherboard to the Bluetooth and AirPort modules, and two of them are mislabeled. I've written up the problem and solution in this article I hope this helps others who have problems with the Mac Pro and Bluetooth, and I hope that Apple notices what the real cause of this problem is.

Fix Boot Camp drive speed in XP on a Mac Pro

Mon, 11 Sep 2006 07:30:03 -0700

Running Boot Camp on a Mac Pro? If so, then you've probably noticed the sluggish drive performance when booted into Windows XP.

Terrabit came up with a solution that uses something called "slipstreaming" that creates a modified Windows XP install CD-ROM with the needed drivers to speed Mac Pro disk I/O from under 4 MB/s to over 60 MB/s. Fortunately, only Mac Pro models are affected by this issue.

I have a simplified version of this technique (with lots of screen shots) on my web site if you need additional details.

Fan noise and/or chirping in earlier G5 Duals

Thu, 1 Jun 2006 07:29:56 -0700

I noticed when browsing some folks' hints for reducing fan noise in the Power Mac G5, that many folks seemed alarmed that their CPU temps would go up unless they had the fans churning by manipulating Energy Saver prefs. CHUD Tools (linked on this page) allows you to turn off processor "napping," which eliminates the relay noise caused by the disconnection of processors in preparation for nap mode.

Don't worry about the heat from specific areas. Just because the temps jump from a very low 9 or 10 degrees Celsius to upwards of 80 degrees does not mean that you are sacrificing your processor or its lifespan. Sure, you may notice a slightly reduced lifespan in processors that worked harder or were cooled more sparingly, but by the time they wore out, the machine would be obsolete and gathering dust somewhere.

The zoned cooling of the Power Mac G5 is brilliant. However, it leads people to believe that a particul...