Danby Beer Keg dispenser fridge.

This depends on the type of system you are using to tap your keg. A standard tap given to you with a keg will not last very long, just less than a week. If you are using a proper kegorator CO2 system, your beer will last at least two months, if not longer depending on the temperature of your fridge.

This solution probably costs more than you care to spend on the problem, but you can buy an external temp controller like this one:
http://www.amazon.com/gp/product/B0002EAL58
You run the probe into the fridge and plug the fridge into the controller. Then the controller will only turn on the fridge if it gets warmer than the temperature you specify.
You might be able to find it cheaper on ebay, too. I'm using this on a kegerator and can keep my beer at a consistent temp.

try changing kegs sounds like the tube in the keg is broken the keg has a tube that runs to the bottom of the keg inside and u push air into the keg to push beer thru that tube and into a cool glass and down to ur gulletbut it sounds like u have a defective keg or an empty keg

how cold is the beer?,too cold and it will foam,can you control the CO2 pressure???too high and it will foam, or you may have a bad keg of beer

Keg's are normally pressurized at 13 psi. If you only set yours at 8 psi then you are going to cause problems. You should always start at least the same psi that the keg is set to. If you can talk to the keg company as they all differ some. Common problem is to lower the psi which will cause foam until you reach about 1/2 full or a little less then you should get less foam but your beer will become very flat. Too much pressure is usually better than too little, even with too much pressure you'll see the beer come out fine but will start to foam when hitting the glass/pitcher. Also note that the coupler's that Danby use are very cheap, check the CO2 vale (between CO2 line and coupler) to see if there are any cracks or anything.

if it is a fridge and not a fridge freezer, then there should be no problem in drilling a hole thro the side

There is a check valve inside the coupler of the danby kegs that cause this problem. The valve is mainly there to prevent beer from back-flowing when changing the keg. Next time you change your keg check for a little black plastic retainer and also a small white plastic ball inside the coupler. Remove those (or just smell it) and you should notice that this is the taste/smell your beer has. I removed mine after this discovery, and there isn't any issues with the taste/smell since. I've heard this is a common issue with the Danby D coupler systems. Also, you won't have any issues with beer backflow when you change the keg, provided the line going to the tap is empty (which usually is if keg is kicked).

try adjusting your co2 pressure down a litle bit it should help

If you are getting foam then finally poors fine you have a temperature problem. If you are getting constant foam then you are probably looking at a pressure problem. First of all make sure that you let your keg sit for at least 4 hours and get down to 38 degrees before you tap the keg. Also ensure that your pressure is set to at least what the pressure is in the keg (generally 13 psi). If you can, try to ask the beer manufactures (if you use a microbrewery) what pressure to set it at. One brew master told me to start at 15 psi and adjust from there.

If you still get foam and you can guarantee that the temperature is correct then you are getting some agitation from something else. Double check all your washers and even check your stop valve on the CO2 line to the coupler. Sometimes the lines are not the correct length or even the correct diameter, when the beer is forced through the line if it starts out thin and then expands or vice versa that gives beer a chance to get agitated and cause foam.

Finally the equipment that is used on these systems are generally not that great. I had a Danby Chill'n Tap and replaced the coupler and the tap and all the lines and that solved my issues, even though my problem was probably a cracked valve for the < $80 it cost me to replace everything it wasn't worth my time to figure out exactly what was wrong with it.