Q&A: MacFixIt Answers

MacFixIt Answers is a feature in which we answer e-mailed questions from our readers. This week there were questions about burned discs no longer being recognized, upgrading from OS X 10.4 Tiger, using a third-party PDF printer in OS X, and CPU temperatures spiking in MacBook Pro systems. We continually answer e-mail questions, and though we present a few answers here, we certainly welcome alternative approaches and views from readers and encourage you to post your suggestions in the comments.

Question: Burned CDs not being recognized anymore
MacFixIt reader "Russell" asks:

When I insert a CD, which I have burned myself, into my MacBook Pro a box shows up and says you have inserted a blank disc. It is clear, by viewing the disc itself, that there is information on it...Commercial CDs show up in iTunes and can be played. DVDs show up on the dvd player and also can be played. I've never burned CDs off my MacBook Pro. I just tried it. I saw there was info directly on the CD itself. It showed up as an error on my stereo CD player. When I inserted it back into the computer it showed there was nothing on the disc.

Answer:
Unless this problem only happens in a specific user account, or has only started after applying a specific system update, then my guess is that your burner will likely need to be replaced. However, there is a possibility that some problem with your OS is the cause. If you have a spare external hard drive available, try installing OS X on it and then booting off the external drive. Try burning a disc or two using the external drive to test it out; if it is successful, then your best bet would be to reinstall OS X to clear up the corruption that's interfering with the burn process (reinstalling should go smoothly in Snow Leopard).

Question: Concerns about upgrading from OS X 10.4
MacFixIt reader "Jelena" asks:

We have a Mac OSX 10.4.11, processor 2.16 GHz Intel Core 2 Duo, Memory - 1GB 667 MHz DDR2SDRAM. I purchased an iPod Touch 32GB but it cannot be used because we need iTunes 10 and the Mac doesn't allow me to download iTunes 10. Please advise if I can upgrade to 10.5 and if I do this, does this mean that it will make other software (Word, Excel etc - I think 2003 version) incompatible?

Answer:
Most software should be compatible with OS X 10.5 and 10.6 (the latest and recommended release). There is always the possibility that you could experience errors after an upgrade, but these should be rectifiable if they happen.

Your system is compatible with 10.5 and 10.6, but you might consider increasing the amount of RAM you have. Depending on your particular system you might be limited to 3-4GB, so be sure to look this up or contact Apple about this. Here is an article that might be useful. It's primarily about preparing for an update to the operating system, but also applies to a full system upgrade.

Question: CPU temperatures spiking on a MacBook Pro
MacFixIt reader "Paul" asks:

I just bought a new 17" MacBook Pro (2.2 GHz), and, while rendering a simple but processor/GPU-intensive image in Smith Micro's Poser, I saw the CPU temperature shoot up to 182 degrees F! The fans went to 4000 rpm, and everything cooled down quickly, but it scared the heck out of me. Can the CPU handle temperature cycles like this, or should I refrain from running Poser on this machine? My two-year-old iMac gets up to about 143 degrees on such a job, but never such a high temp as this. Please advise!

Answer:
180 degrees F (~82 degrees C) is not a particularly hot temperature for the CPU, and is within the expected range. The Core i5 and i7 CPUs used in Apple's MacBook systems have a maximum rated temperature of 105 degrees C for the CPU core, and 100 degrees C for the graphics and memory controllers on the chip (according to Intel's CPU datasheets). I would say as long as the chip does not get above 90-95 degrees C then you should be fine. The mobile processors will get hotter for similar tasks than the desktop CPUs, which are rated about 20-30 degrees C less than their mobile counterparts.

The processor will immediately heat up when you start doing CPU-intensive tasks (games, 3D rendering, video encoding, and so on), and definitely can spike very quickly. It is not uncommon to see a mobile CPU go from an idle temperature of 55-60 degrees C to close to 80 degrees C in a minute or two. I just launched a 3D game that spiked my MacBook Pro's CPU cores to 83 degrees C and 86 degrees C from their idle temperature of about 57 degrees C (now at 62 degrees C about a minute after quitting the game).

Question: Using third-party PDF printers in OS X
An anonymous MacFixIt reader asks:

I installed the cups-pdf printer from bitbucket.org. It shows up as a printer, which I select and can print to. However, I don't seem to have any PDF file after it has closed. Where is it, or what do I need to do to make it work correctly?

Answer:
I am not familiar with the cups-pdf printer software, but according to the developer the PDFs should be placed in the /Macintosh HD/Users/Shared/CUPS-PDF/ folder (the Shared folder is one level up from the root of your home directory). As an alternative, OS X has built-in PDF rendering software that can be used to create PDFs from a printed page, if that will be of any use.

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