Apple Inc’s (AAPL.O) surprise warning that it will likely fall short of this quarter’s sales target due to the coronavirus epidemic points to much pain for its chip and other suppliers as well as for rivals who also rely on China to build their products. Revising guidance set just three weeks ago, the world’s most valuable tech company said while many factories that make iPhones have reopened for work, they were ramping up more slowly than anticipated. The outbreak, which has infected more than 72,000 and prevented many employees from returning to work due to travel and quarantine restrictions, was reverberating throughout the U.S. firm’s supply chain, a source familiar with Apple’s operations in China said. “If one component factory stays closed and they’re the only supplier, then everyone has to stop and wait. And if there are two suppliers and one is shut down, then we need the other to do more,” said the source who was not authorized to speak to media and declined to be identified.