DYNACO ST-80 PC-18 AND PC-19 COMPLETE QUICK REPAIR KIT. THIS KIT INCLUDES EVERY TRANSISTOR AND DIODE ON ONE CHANNEL OF THE PC-18 CIRCUIT BOARD, TWO OUTPUT TRANSISTORS, PLUS ALL THE DIODES ASSOCIATED WITH THE PC-19 POWER SUPPLY BOARD. (D1 THRU D7 , AND Q1 THRU Q6 --- 13 SEMICONDUCTORS IN ALL) INPUT AND OUTPUT DEVICES ARE SCREENED FOR NOISE AND/OR GAIN. KIT COMES WITH SCHEMATIC, INSTRUCTIONS, AND PC-18/PC-19 PICTORIAL SHOWING DEVICE LOCATION AND EBC ORIENTATION. DUE TO CHANGES IN THE ST-80 DESIGN, Q3 AND Q4 ARE TIP PACKAGE (FLAT WITH HOLE)AS OPPOSED TO TO-39 PACKAGE (ROUND CAN) TRANSISTORS WHICH IS TO THE LATEST REVISION. IF YOU WANT EARLIER REVISION PARTS, CONTACT ME FOR AVAILABILITY AND PRICING.