3.5mm jack pin layout help needed

[peps1]

I was salvaging some motors out of an old CD drive, and thought I would take the surface mount 3.5mm jack and use it to build a little Ruby headphone amp.

Being new to all this audio action i was just wondering if there was a standardisation for the pin layout.....has 3 in the same layout as this one below. 

[peps1]

also has very little marks saying  P, O and TC ?

[manis404]

the pin closest to the 'hole' is ground. The two others are left and right.

[yeeshkul]

the safest way is to plug jack in and use DMM to find shorts.