Might be a few months late with this but I just joined here. We have a DV441 in a 2001 SMB that runs and doesn't want to cycle until it's turned all the way down on 1 or 2, and it keeps the box 30° inside, and down to 25° at night when the ambient temps drop.
I found a troubleshooting guide that listed the specs for the thermistor in 10° ranges of temperatures, and using that I figured out that the thermistor on ours is pretty much not within those acceptable ranges. There is a connector you can disconnect and with a multimeter you can read the DC resistance of the thermistor when the box is cold, I bet you will find your thermistor is outside the acceptable range.
While looking for parts to see if the thermistor could be replaced, I came across this Articca adjustable thermistor and ordered one since it sounds from the description like it will let you control the temps of the box from the adjustment. All I can do it try it, since ours is not working right, and it seems like the only problem with it is that the resistance of the factory thermistor is off.
I have had our fridge sitting in my workshop on a table running for a few days, other than it keeping the box too cold for anything not to freeze, it is cycling and working perfectly.
Since the adjustable unit was just ordered this morning, I should know in a week or two if it is fixed. $26 beats the crap out of $700 for a new fridge!