My employer didn't know how to withhold PA taxes so left the state blank on my W-2. I need to determine my taxes due. How do I get turbotax to make that calculation?

[Nobushi]

Right now Turbotax ignores that W-2 altogether as if that income doesn't exist or count, but it does.

[LeonardS]

If your employer did not withhold and report your PA income and tax withheld there will be no information on lines 15, or 16 for state information, then you should fill in boxes 15 & 16 to report your wages earned in PA.

For line 15 enter PA for state and any random letter-number combination for the Employers state ID number 

For Line 16 enter the amount from Box 1 of your W-2

TurboTax will include your W-2 wages as Taxable by PA after you make these entries and calculate any tax you may owe to PA