Since these problems surfaced, Microsoft has attempted to modify the console to improve its reliability. Modifications include a reduction in the number, size, and placement of components, the addition of dabs of epoxy on the corners and edges of the CPU and GPU as glue to prevent movement relative to the board during heat expansion, and a second GPU heatsink to dissipate more heat. With the release of the redesigned Xbox 360 S, the warranty for the newer models does not include the three-year extended coverage for "General Hardware Failures". The newer Xbox 360 S model indicates system overheating when the console's power button begins to flash red, unlike previous models where the first and third quadrant of the ring would light up red around the power button if overheating occurred. The system will then warn the user of imminent system shutdown until the system has cooled, whereas a flashing power button that alternates between green and red is an indication of a "General Hardware Failure" unlike older models where three of the quadrants would light up red.