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TRACE ELLIOT
SERVICE MANUAL NO. SM00022
ISSUE 1
Date: October 28, 1996
Product Code : T1400
Model No : TEK 150
Technical File No : TE00022
Issued by:
Trace Elliot Limited.
Blackwater Trading Estate
The Causeway, Maldon
Essex 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 T2SA1695's
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