Swapping hard drives between Mac Minis

Someone wrote to me describing a somewhat bizarre home automation scenario and then proceeded to ask me a question. I answered to it but his mail server seems to be misconfigured and I got a 550-inconsistent or no DNS PTR record for x.y.z.q error.

I don’t want to throw my answer away just because of a misconfigured mail server. So let’s imagine for a minute that this is the Questions and Answers section of the website. Here we go with today’s letter (slightly edited for simplicity)!

I have a MacMini MB138xx/A (bought early 2008) which wakes up the monitor randomly from sleep. Unplugging the mouse does not help. Three other Mac Minis I have do not have this problem and I assume it is a problem of the I/O chip on the motherboard.

Why I need 4 Mac Minis: I run some home-automation software on them.

For that one misbehaving Mac Mini I decided to replace the motherboard. But after looking for a replacement motherboard for a while, I found it easier to buy a used Mac Mini from Ebay, same model MB138, and just put the harddrive of the old one into the newly purchased one.

Then I read your tutorial on how to replace the harddrive. Thank you for that, I am sure this will be helpful!

You did not mention the exact Mac Mini model anywhere, but I hope the tutorial fits to model MB138xx/A

Before I buy a used Mac Mini and start my operation, I would like to ask you if you see any difficulties/issues/problems with my plan? Do you think the replacement-Mac will recognize the new harddisk and work right away or do you fear any settings are maybe stored on an Eprom somewhere on the board, so I eventually can not get it to run?

Regards,
T.

ANSWER: Your setup is the weirdest thing I’ve read this year. Feel proud!

My tutorial was written for a Mac Mini bought in April 2007. Some people have reported that some screws were in different places in newer computers, but they seemed to have found their way around it. It’s somewhere in the comments if you read them.

I don’t quite know if there are “settings” stored in the eeprom… apart from the date and time. The worst that might happen is that you have to set the date and time, I guess. In a bad case you can always try to reset the eeprom.
I would think that if you change one hard drive to another computer it should work fine. But you never know with macs, they are weird computers :-D

Good luck!

sole

Perhaps some enlightened reader has experience swapping hard drives of mac minis and can shed some light on this question. I have put drives of other machines in computers some times, and generally the operating system did boot although maybe things were a bit weird (as in, loading a driver for a hardware peripheral that didn’t exist). But this was with Linux and Windows. Who knows what Macs would do!?