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I installed a new ssd in my macbook and moved the harddrive into the optical bay following guides on ifixit. I was successfully able to clone over the drive and everything boots up, but the OS is sluggish, the fan is really loud and the battery in not detected. I have figured it needed an smc reset, but nothing is working. I have tried holding the power button without the battery plugged in dozens of times, as well as holding shift, ctrl, and option. I have even tried manually flashing the smc firmware and still got errors. I am not sure what else to do and could really use some help.
First I would put the HD back into the HD drive bay. You don’t need to rotate the drives when you setup a dual drive config. Keep in mind the HD SATA port has crash guard protection the optical drive doesn’t. So you are putting your HD at risk moving it over. As to your problem you are facing here you are likely hitting a known problem with the HD SATA cable with SATA III drives. The first units still had the older cable design which had issues. You’ll need to replace it. I would recommend you visit an Apple Store or Apple authorized service center to have it replaced for Free! As Apple has a program to replace the cable under a non-published extended warranty program. If you can’t get done as you don’t have anyone near you here is the IFIXIT guide: MacBook Pro 13" Unibody Mid 2012 Hard Drive Cable Replacement
