hi,
this wonder like a charm. Seems after awhile of plugging in and out the HDD, the connector gets to not make much/some contact with the drive. and yes the tape goes TO THE UPPER PLASTIC SIDE (Just slide the tape in secure it in place with a flat screwdriver) and bam. HDD back on. This issue has been a headache for me ( Do repairs for a living) and bought a cables for the same mac but didn't have any results till i id this as explained above. highly appreciated. saved me a client.
Keep repairing!:)