Hello, I've got that left out feeling, amplified by attempts at clever but non standard upgrades that have other consequences.
Main issue. Mac Mini late 2009, the latest version not able to be upgraded to Sierra. :-( 8mb RAM It was running out of hard disk space, feeling slow since I got a MacBook Pro and the DVD drive didn't seem to function, so I bought a Samsung 850 500mb SSD and a cheap adaptor and replaced the DVD drive with the SSD internally. RESULT: great performance for about half an hour, then it would stop responding and behaving like a HDD failure with Finder becoming unresponsive. Unplug and restart and the SSD would flash once then start up on the main HDD that I'd cloned from until all was working well - fortunately. I read there may be issues with the amount of power available to the old DVD on start up, so removed all accessories, including unplugging the monitor, for a restart. The SSD fails to act as start up disk, or load to the Finder, on a restart UNLESS the computer is cold. A cold restart and it works fine for about half an hour. Question: Is there a way of determining internal device power usage? Could this be a power supply problem? Machine Two. Not seeking answers, just so you'll feel sorry for me. ;-) MacPro 1,1 32gb RAM It should run not El Capitan being well out of date, but by some magic software trickery, it does, and runs quite well. Downside is none of the USB ports work. I've loaded all my spare HDD into this machine so it backs up internally on one of four internal drives, not ideal, and the only way I can get data in and out apart from Ethernet is to restart it on a old operating system so the USB ports work, transfer the data (photos) then restart it in El Capitan. Sigh. And then there is the Mac Plus in the cupboard!!! Ideas regarding troubleshooting the SSD installation in the Mac Mini would be appreciated. Cheers Tim Sent from Tim's Retina iPad 2 -- The WA Macintosh User Group Mailing List -- Archives - <http://www.wamug.org.au/mailinglist/archives.shtml> Guidelines - <http://www.wamug.org.au/mailinglist/guidelines.shtml> Settings & Unsubscribe - <http://lists.wamug.org.au/listinfo/wamug.org.au-wamug>

