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Onkyo TX-SR705 phono

perhaps the wrong place, but has anyone here ever worked on this rcvr?
The phono pre in mine is bad.
The service manual seems to indicate that it may be a separate pcb that plugs in.
That is what I'm trying to determine before I open it up.

Re: Onkyo TX-SR705 phono

The IC that amplifies phono input is IC1701; seems to be on the SD5 Microprocessor board. That is a NJM4580M-D (a common IC). I would check for 6.8 volts + and - at that IC; if it is low or missing then I would assume the IC is bad and also check resistors R1701 and 2 (68 ohm) as they may be open. These resistors drop power from the + and - 12 volt lines; I would check those voltages also.

Re: Onkyo TX-SR705 phono

thanks very much. I'll check that out.