Responded to no ac call for second floor system. Upon arrival turned system on at thermostat, indoor unit started. Noticed that the outdoor unit fan wasn’t spinning. Found defective capacitor. Replaced capacitor and system started up. Let run for 30-35min and checked pressures. Pressures are slightly off, and system is struggling to cool. Noticed that system is short on return. Advised customer that I do not recommend doing any repairs on the second floor system, system is 20 years old and R22. Left system running with new capacitor, system not cooling efficiently.