Arrived at location on 3/29/22 - On site for unit not cooling. Checked unit operation, found unit with no gas in system. Pressurized with 50psi of nitrogen. Leak checked with D-TEK 3 -Refrigerant. Leak detector found small leak by in shredder pin. Removed installed new pin, pulled a vacuum it held charge unit with 3.7 oz of R290. Unit temperature dropped to 36f unin fully operating.