Trace Elliot GP7 150-300watt SM 电路原理图.pdf

TRACE ELLIOT SERVICE MANUAL DATE : December 29, 1999 Product Code: N/A Model Number : GP7 300 WATT SM SERIES This unit has used two issues of 300 watt MOSFET power board. The Bi-polar Bear and the 300 Mosfet Board Details for both are included in this manual. You should check which board you have in your unit before attempting any repair. The Bi-polar board is marked PC00026 The MOSFET board is marked PC00083 Issued by: Trace Elliot Limited Blackwater Trading Estate The Causeway Maldon Essex England CM4 4GG Important Notice To make the bi-polar 300 watt bass board reliable the following guidelines must be adhered to. When a board need to be serviced it is advisable to replace both the Output Transistors and TIP31 and TIP32. Also it is advisable to replace TR11 which is situated under the rear of the heatsink. The Output device should only be T2SC4468 and T2SA1695s The Drivers should be of the same manufacturer as each other to ensure stability. And TR11 is a T2N3904 as listed on the parts list. TR11 need to be completely covered in Heat Transfer Compound (HTC) This is to ensure that it keeps the unit biased correctly even when the unit gets hot. If TR11 is not covered then the fan can cool this component down and give the board a fault reading of temperature and provide and inappropriate bias. When adjusting the bias on the scope, make sure that the crossover distortion is just not visible. Too far beyond this point will over bias the unit. Use a Shake-proof washer under the pcb earth point to ensure a permanent connection and prevent crackling noises in the future. Paul Mathews Jan 2000-01-25 cd0086x4.sch-1 - Sat Dec 11 11:04:47 1999