Officials with Metro say a failed computer module is what caused the glitch over the weekend that resulted in delays exceeding 30 minutes across the system.
Officials say the failed module was in an information management network device. Once the computer module, which is said to be about the size of a pizza box, was replaced in the early morning hours before the start of train service, the errors that had occurred in the system stopped.
The computer problem on Saturday afternoon and early Sunday morning affected an information management system that allows controllers in Metro's Rail Operations Control Center to see where trains are on a dynamic map and to remotely control switches.
Officials say all safety systems that keep trains properly spaced remained fully operational during both occurrences.