What everyone said is true. If it is indeed a refurb return that thing for an exchange you should never have to tweak a new/refurb drive. And if you are tweaking it now and you drop down to 2.8 ohms you will be lucky to get a year more likely 3-6months on a lucky day.
As far as the Multi Meter goes I have different ones from Flukes to Harbor freight $5.00 Specials and to be honest I use the Harbor Freight a lot because it has the smallest tips to really get it those tight spaces and I can leave it anywhere and not worry about it walking away. Set it to Ohms 20k and do NOT go below 2.8 ever.
I just did the pot tweak on my Samsung because it wouldn't read backups. Thank goodness for the tutorial on how to do it, because my drive works much better now. I guess it's only a temporary cure, from what others have said, though.