This part is a kind of semiconductor called STK407-240.

Function of this product has 3-channel AF Power Amplifier.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

S T K 407-240 (IC 3402: A MP A S S Y ) 3-c hannel A F P ower A mplifier B lock Diagram HT Z-7, HT Z-C 7, HT Z-S W7, HT Z-S T 7 http://www.net TR 2 TR 1 C1 R1 TR 3 TR 4 D2 R3 TR 9 TR 6 C2 R4 TR 8 R5 R6 TR 7 T R 10 T R 12 R9 R7 D1 D3 D5 T R 22 R 16 R 19 T R 19 R 17 R8 T R 11 T R 23 R 18 T R 20 T R 21 T R 18 R 13 D4 T R 14 T R 13 C3 T R 25 C5 R 21 T R 26 D6 R 23 T R 33 T R 30 C6 R 28 R 24 T R 32 R 25 R 26 T R 31 R 27 T R 34 R 29 D7 T R 35 C4 R 14 R 15 R 11 T R 16 T R 15 T R 28 T R 27 TR 5 R2 T R 24 T R 17 R 12 T R 29 R 22 T R 36 PT1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 http://www.net/ http://www.net datasheet pdf - http://www.net/ [ ... ]

STK407-240 PDF Datasheet Download