**Tip:** When determining whether the system is blocked by ice or dirt, you can judge by observing the location of frosting on the capillary tube of the outdoor unit. If frosting starts from the inlet of the capillary tube, it indicates a dirt blockage; if frosting starts from the outlet of the capillary tube, it indicates an ice blockage.
**Analysis and Repair:** When the air conditioner was initially turned on, the cooling function worked normally, but after about 25 minutes, the system pressure and current dropped. Since the cooling function was basically normal for the first 25 minutes after turning on, it was preliminarily analyzed that the system might be experiencing an ice blockage. After opening the top panel of the outdoor unit, it was observed that there was frosting at the outlet of the capillary tube. Heating the frosted area with a lighter restored the pressure and current to normal, confirming that the system had an ice blockage.
First, the refrigerant was recovered into the outdoor unit, then a drier filter was installed on the low-pressure pipe of the outdoor unit. The purpose of this was to dry the refrigerant. After re-evacuating the system, the unit was restarted until the ice blockage was completely eliminated (Beijing Panasonic Air Conditioning Repair Center). After removing the drier filter, the cooling performance returned to good condition.
**Technical Analysis from Beijing Panasonic Air Conditioning Repair Center:**
The Panasonic air conditioner worked normally when it was first turned on, but after 25 minutes, it stopped cooling.