No errors reported by SuperDuper! app, cloning process 67% complete. Seems the drive is OK.

Struck read/write errors on a Thunderbolt 1-attached SuperDuper! backup drive. I’ve has suspicions about the T/bolt cable for a while. Fortunately, for this Seagate GoFlex interface I also have a pair of USB 3 interfaces & a FireWire 800 adaptor, so I’m trying the backup clone again, this time on USB 3. Thus far, no errors reported.
I have another T/bolt cable somewhere so I’ll use a process of elimination to work out if it’s the other cable or the interface that’ Going wonky.

This arrived today from Amazon, sourced from UK. Took two weeks to arrive. Image Darts can be stored/carried fully assembled.

Further research suggests early 2012 retina MBPs should be avoided as they also experienced the lead-free solder problems. Now, Dale, do you need a 15-inch model? The 13-inch ones are also pretty good but never had quad-core processors.

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I go my elements confused re the solder in the 2011 MacBook Pro range. It is lead-free solder that was used, not tin-free as previously stated. I have updated that original blurb.

2012 onward would be advisable. That's when the Retina models began appearing. These, of course, lack optical drives but any USB optical drive should work fine, no drivers needed.

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It isn't a bad device, except for the abysmal 2 MP camera.

I don't know about the 7 years of spares rule, I do know that in Australia, Apple still advertises its stuff as having a 12-month warranty period even though consumer laws state categorically that the statutory warranty on all new products is 24 months.
If challenged re the 12 month period, Apple caves in, though.

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Such replacement motherboards might be a bit thin on the ground after 7 years. I used my MBP mostly was a desktop machine, lid closed & a 20" monitor attached. So its replacement by a Retina 4k 21.5" iMac is a logical progression.

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Tomorrow I fire up the new garden tool for the first time. I bought it last weekend & assembled it today. There's a common power & drive unit, with a 34 cc 2-stroke petrol engine and five swappable attachments: lawn edger; line trimmer; brushcutter; extension pole chainsaw & a hedge trimmer.