Components
Capacitor Electrolyte Leakage

Capacitor electrolyte leakage - Aluminum wet slug capacitors have a tendency to leak. This unit functioned for a number of Shuttle missions, but ultimately the electrolyte leaked, the capacitor failed and the printed wiring assembly was damaged.

Reference :
NASA-STD-8739.3
10.4 Solder Cleaning
Final Cleaning.
After cleaning, there shall be no visible evidence of flux residue or other contamination when examined. PWA cleanliness shall be verified in accordance with Chapter 14.

13.6 Inspection Criteria
Rejection Criteria.
The following are some characteristics of unsatisfactory conditions, any of which are cause for rejection: (9) Flux residue or other contaminants.