Blockages are as hard as a weld and are attached in the upper coil area and CANNOT be broken loose. So, burping just rearranges the Ammonia temporarily to work a little longer. It works but NOT AS WELL AS BEFORE THE BLOCKAGE. IT WILL FAIL AGAIN. Rebuilders cut out the tubing where the blockage is on blocked units and then weld a new upper tube assbly in place, then charges the cooling unit. THERE IS NO WAY THAT MOBILE TECH FOUND A BLOCKAGE, UNLESS HE STUCK AROUND FOR 2 OR 3 DAYS AND DID VARIOUS TESTS. TEMPORARILY UNBLOCKING A UNIT REQUIRES THE REFER TO BE TURNED UPSIDE DOWN FOR 24 HOURS AND THEN RIGHT SIDE UP FOR 24 HOURS. Then start a cooling process. You could have just had a glitch and if the refer continues to cool (below 38 degrees in the refer and below 10 degrees in the freezer), I would not worry about it. Also, it could have been as simple as the rear cooling fans did not run. Did the Mobile tech checked those? Doug
PS, is the refer in a slide room?