Flat beer in new kegerator

Hi all, I guess this is my third thread now related to my kegerator project (what can I say, I love this kegerator). I am sure the answer to my question is somewhere buried in the forum but I searched and couldn't quite figure it out so I hope you will forgive me if this is a dupe.

I have 2x 5 gallon kegs from six point brewery sitting in my kegerator ready for a party tonight. I had them sitting in my apartment warm for about 2 weeks, then put them in and started chilling them about 36 hours ago. Last night (so around the 24 hour mark) I tapped them, threw on the CO2 at 12 psi and tried pouring a few to see how they are doing. The flavor is delicious, so that isn't a concern. But the beer itself is coming out flat. There is plenty of head on the top (borderline too much foam, I'll work on that later though), but the beer itself isn't bubbly/effervescent. I called the brewery and the guy (who was right in the middle of brewing but stopped to try to help me out) I talked to seemed a little concerned that I had left them warm for so long. Was that a bad idea? He also said I should check to make sure the CO2 is actually reaching the keg properly.

Those seem like ideas worth trying, but does anyone else have any suggestions? The beer is about 40 F right now. This morning I cranked the pressure a little higher, flipped the kegs upsidedown and then rightside up 3 times and tried pouring another beer. This one was a little bit more carbonated than last night but still not ideal.

How long are your serving lines and what is the inside diameter? If you have short lines, or 1/4" ID lines, you really need to dial the pressure down to about 5psi to serve. It's possible you're losing all your gas in the pour.

+1 Bobby

Also... I find I get better carb when I take longer at a lower pressure to force carb it. The "one day" high pressure works in a bind...but...usually the overall carb of the beer is low.

-Will

My lines are 5 feet long 3/16" tubing. I didn't realize that line length could take out all the carbonation, I thought it just altered the head. I guess I have more studying to do.

I'll definitely try it at low pressure, I didn't even think that lowering might help, all I have done so far is raise pressure.

As for force carbing... does it make sense that this beer lost all its carbonation? Was letting it sit warm for 2 weeks after I bought just a stupid thing to do?

Thanks for the help!