Hitachi Receiver Model SR-604

Discussion in 'General Electronics Chat' started by cadman, Oct 5, 2005.

  1. cadman

    Thread Starter New Member

    Oct 5, 2005
    My circa 1979 receiver is wanting to breath its last but I refuse to let it! I've previously had to have the left channel repaired, now it's the right. Can anyone point me to possible culprits? I've done the obvious checks (switching speakers...) I do not have a service manual for it :(

    Thanks in advance for any help!
  2. mozikluv

    AAC Fanatic!

    Jan 22, 2004
    hi cadman,

    you didn't mention if your receiver is a tube or discrete. you have to work your way backwards. you start first by checking the voltages from the left channel and record them. then do the voltage check on the right channel and compare. start checking from the output transistors, then the driver transistors, then the predriver transistor if there is, then the voltage multiplier transistor, then the differential input transistors. any discrepancy that you find is probably the defective part, remove the transistor and do the transistor test, if ok, check the value of the bias resistors and compare to the body band value, if the value is beyond +/-5% or 10%, replace it. then check the coupling caps.

    that's all for now.

  3. cadman

    Thread Starter New Member

    Oct 5, 2005

    Thanks for the tips and I'll give it a whirl.

    It's discrete by the way.