Got a call from one of my customers, pizza joint, that he was having issues with one of his other stores. It is about 45 miles away. He didn't think I would travel. Long story short, walk-in cooling keeps having issues. They have worked on it 5 or 6 times over past 6 months. I told him I would take care of it for him. Called store, they say unit froze to compressor. I have them turn off breaker to condenser to deice. Get there evap & condenser dirty, clean both. Start up unit, bubbles in sight glass, evap temp 30, suction line 30 ( no superheat ). First thought dirty txv bulb or txv open to far. Pull off bulb and found this. Yes, a new txv makes unit work great now.
From My Evo 4G