After examination of IC802 (STR-S6307) and the transistor Q801 and other damage. Not found when replacing Q801 (2SA564A) the same model tube, with 2SA1015 transistor manual substitution after the investigation, but the emergence of new fault grating turn on and off, and the reason is: ignore the transistor characteristic frequency parameter ft. Check the manual 2SA1015 low frequency tube ft of 80MHz, while 2SA564A to 150 MHz. Check the machine circuit, also found Q233 tube 2SA564A (indicated on the drawings available C558-generation), remove the mounting position to Q801, Q233 situ with C558 substitution, boot everything back to normal.2hKservice manual download site