Thanks Ronni The drive is not bootable, data only. For the moment, by some unseen magic!, it has repaired itself. I shut down each night overnight and restart next day and there it was. I note your two links for further notice, if needed! Many thanks Severin
> On 29 Oct 2015, at 2:20 pm, Ronni Brown <[email protected]> wrote: > > >> On 24 Oct 2015, at 3:35 PM, Severin Crisp <[email protected] >> <mailto:[email protected]>> wrote: >> >> I have an Elgato 500GB SSD Thunderbolt connection which has disappeared >> since I did the latest security update on Yosemite. It appears in System >> Report as physically connected to Thunderbolt but is not found with Disk >> Utility or Disk Warrior. Shutdown and restart does not bring it to light. >> I have not yet tried just unplugging and replugging everything. >> Suggestions welcomed! >> Severin Crisp > > Hi Severin, > > I somehow missed this post. Has the problem been rectified our do you still > require help? > If you do require help - Is the external drive a bootable drive? - Or is it a > secondary (data) drive? > > The System Management Controller, NVRAM, and PRAM all store parameters that > the system can use to store system settings including boot information. These > can become corrupt, and if they do, a reset may make a once invisible drive > visible again. The following two links identify how to reset these parameters: > > <http://support.apple.com/kb/ht1379 <http://support.apple.com/kb/ht1379>> > > <http://support.apple.com/kb/ht3964 <http://support.apple.com/kb/ht3964>> > > The resets above should be performed when problems exist, regardless of > whether or not the external drive is bootable. > Before doing anything else, these checks should be done because they're > easily to do and sometimes work. > > Cheers, > Ronni > > 13-inch MacBook Air (April 2014) > 1.7GHz Dual-Core Intel Core i7, Turbo Boost to 3.3GHz > 8GB 1600MHz LPDDR3 SDRAM > 512GB PCIe-based Flash Storage > > OS X El Capitan 10.11 > >> ____________________________________________________ >> >> Assoc Prof R Severin Crisp, FAIP, FIP, CPhys >> 15 Thomas St, Mount Clarence, Albany, 6330, Western Australia >> ph (08) 9842 1950 ( Int'l +61 8 9842 1950) >> mail to: [email protected] >> <mailto:[email protected]> >> ____________________________________________________ > > -- 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> ____________________________________________________ Assoc Prof R Severin Crisp, FAIP, FIP, CPhys 15 Thomas St, Mount Clarence, Albany, 6330, Western Australia ph (08) 9842 1950 ( Int'l +61 8 9842 1950) mail to: [email protected] ____________________________________________________
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