By Graham K. Rogers

A week or two ago I went into the office found that the iMac I keep there had a failed disk. I ran some checks in the hope that this wasn't really so, but there was an inevitability about the test results. I took the iMac to the campus store and the department technician ordered me a replacement hard disk which arrived the next day.

With the speed that things had gone initially, I had hoped to have the iMac back a little sooner from the repairer, but when I went to the U-Store after a few days and asked, there was a problem with the hard drive. There had been a mis-communication. I had bought a 2.5" 500 GB drive through the department techie and the shop told me this was the wrong size. What I wanted was a 5". Read on, for qualification of this.

I asked the staff member at the U-Store -- the Apple retail store on campus -- to have the Toshiba drive brought back as I would have it changed. When I told the department technician, he spotted immediately that my information was wrong. There are no 5" hard drives: did the shop guy mean 3.5"?

He may well have done, but I am fairly clear on the difference in Thai between 5 and 3.5 and sure that what I was told was 5": wrong as it may be.

"Why did I ask for a 2.5" drive?" I was asked.

"I didn't." That was what I was given.

"But you asked for it."

No I didn't. Yes you did; no I didn't. Yes you did; no I didn't. Yes you did; no I didn't. Yes you did.

I have the wrong disk. A new one is needed. This will be rectified.

I checked first on the Apple Support pages and confirmed what I already knew: that the SATA drive as originally installed on the early 2009 and early 2008 20" iMacs was 320 GB, but I was unable to check the dimensions of the disk itself.

Over on iFixit however, once I had dug down to the iMac pages, there were two replacement drive options: 1 and 3 TB (now there is an idea). When each was highlighted it showed the dimensions to be 3.5" x 1" which was as the techie had assured me and I had no reason to doubt him. But with two miscommunications, I am doing my best to avoid another.

When I made a visit Monday I was told that the Toshiba disk had not yet been returned but would be there that afternoon. A later phone call put that back to Tuesday afternoon. I picked it up then and took it to my office to wait for an exchange.

On Monday afternoon the following week, the replacement disk arrived at the office: a WD 500 GB. I handed this over at the U-Store and hope to have it back by the end of the week (fingers crossed), just in time to prepare for Mountain Lion.

See also:

• Hard Disk Failure on the Office iMac; and
• Hard Disk Failure on the Office iMac: Part 2 - Data Recovery

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.