Sony HT-5500D receiver problems
 

This unit will come on and the protection display will come on. I have
had the volume turned down and I have checked the speakers for any
problems. I have even checked all the output transistors and various
components around the outputs. Has anyone run into this problem with
this unit? Would anyone have a schematic or service manual that they
could email me? Thanks, Rob

Sony HT-5500D receiver problems
 

"rob34" wrote in message
...
This unit will come on and the protection display will come on. I have
had the volume turned down and I have checked the speakers for any
problems. I have even checked all the output transistors and various
components around the outputs. Has anyone run into this problem with
this unit? Would anyone have a schematic or service manual that they
could email me? Thanks, Rob


The receiver portion of this system is the STR-K840P.

If the outputs are OK, the most likely culprit is IC501, an STK350-230.
You should measure DC with respect to ground from the center of each emitter
resistor to confirm a DC offset. Most of the amp channels use UPC series
drivers which are quite reliable, the one channel using the STK is a
frequent offender. Sony won't allow me to distribute their service
literature.

Mark Z.