Checking in a computer for a variety of issues as described by a customer can provide more issues than potential resolutions. I’m certainly not suggesting to discredit customer’s claims on what they may perceive to be the issue, it’s just that they tend to have a limited technical vocabulary. This is where consulting a system’s Console log can be invaluable because it notes problems in absolutes, which can pin point issues more effectively.
Considering the immense insight that Console can provide when diagnosing an issue, there is just too much code to cover in this article. For the sake of time, I’m drawing focus to the ever so helpful “previous shut down code” logs.
To locate these — if present — you simply open up Console in the utility folder. This can be found by selecting Go > Utilities > Console, or by simply typing “Console” into Spotlight in the top right corner. Once open, there is a very helpful search field to help narrow one’s research into a specific issue. I often find “shut down”, “sleep”, and “fail” to be great modifiers.
In the case of a particular unit that was checked in today, the symptom as noted by the customer is as follows: “MB is ‘screaming’ at random times during use. Loud noises coming from the machine.” As a technician, ‘screaming’ is a term that isn’t widely used, and without more specifics, can pertain to just about any hardware component that has moving parts (i.e. hard drive, fan(s), and optical drive).
Upon booting the system, I was not able to replicate the issue, but by digging through Console, I did discover that the system reported a -60 previous shut down code multiple times. -60 indicates a bad master directory block, which helps isolate the issue to a potential software corruption on the drive. In turn, this informs me to proceed with a split-half search of the drive by running diagnostics to check the integrity of the operating system, and to determine if the issue is either software or hardware related. Although this isn’t a precise point of failure, without console I would have been trying to fish out the problem without a fishing pole.
I’ve included a file with a list of negative error codes (0 to -261) with brief descriptions that may be helpful to reference. You can grab a copy here.