"not carbonated" is a state of mind. Does it pour without excesseve foaming? If yes, you continue to have a problem If no, carry on. Does it pour with a head? If no, then stop tilting your glass like a local-pub-barwench, harden up, and pour straight, like a man. If yes, then continue to next question/statement....you pour without excessive foaming; you get a good head on the beer; BUT; you don't have lots and lots of bubbles rising through the glass.....welcome to correctly carbonated beer!! very different than the over bubbly, alka selzer - like rubbish poured (but mostly spilled) at your local pub.
Irrespective of whether I am right that it's a line length issue (even though I am), or others are right that it's overcarbonation (although, how can you overcarbonate with the 'let it sit for a week on serving pressure' aproach?????....now there's the real fly in the ointment, because you can't
. ), the main point you should take from this painful lesson (and yes, it is a painful lesson. I remember oh so vividly when I went through it), is the final sentance in the balancing a draught system thread......
"DON'T SCREW WITH THE REGULATOR!"
So....if you know what volume of CO2 you want, and you have a stable temperature, and if you charge the keg by sitting for long enough (ie 1 week for 2.5vol or less, perhaps slightly longer for higher saturation levels) at the temparuture
required for that saturation level of CO2.....
Your keg will be perfectly carbonated as per your requirements
. You could leave it like this for a year, and the level of saturation of carbon dioxide within the system will be relative to the combination of temperature and pressure, and is unable to exceed the level of saturation which is relative to the combination of temperature and pressure.
Any pouring issues after this will be due to imbalance of the system
. Either, line too short, causing excessive pressure in the pour (ie, commonly reffered too as overcarbonated: as I have mentioned previously, overcarbonated relative to the system in place, rather than to the required saturation level of CO2), or, the line is too long, causing underpressure pouring, and degassing within the line itself (ie, commonly referred to as undercarbing, again, undercarbonated relative to the system in place).