I have had my kegerator up and running for a while...just pulled a pint....went back for a second pint ( different brew) and nothing came out of the tap. Opened the kegerator and my pressure was bottomed out on the guage to the tanks...turned it up and everything seems fine now. I hooked a fresh keg up to the co2 yesterday but other than that it hasn't been touched in a few days. I have checked everything for leaks and can find none...any ideas?edited to add that the tank is a big one just filled and only has a couple kegs off of it.