If Me.Type1 = True and Me.Type2 = False Then
    PCType = 1
ElseIf Me.Type2 = True and Me.Type1 = False Then
    PCType = 2
ElseIf Me.Type1 = True and Me.Type2 = True Then
    PCType = 4
ElseIf ... <further conditions go here>
End If    
This is going on the assumption that you want to hardcode the value of PCType for every single different scenario (i.e. setting a different PCType value for when only check1 and check3 are ticked, another unique value when all three are ticked etc)
You can also simplify it further by using branching if statements:
If Me.Type1 = True Then
    If Me.Type2 = False Then
        PCType = 1
    ElseIf ...
    End If
End If
However it's hard to give examples of this based on the information you have given.