I'm working on an AU-9900 that came to me with no output at all. It powers up, comes out of protection but no sound from either channel. A quick check show no output from the preamp. I've isolated it to the function switch on the F-2569 input board. The signal path goes directly from the aux input to pins on the function switch but never gets out of the function switch. I have the board out and I'm assuming
Has anyone run into this before? This is one complected input signal path. Before I take the function switch off the board and tear it apart, I want to make sure that the dropout is not being caused elsewhere in this complected signal path.
Here's a clip of the schematic.
There are three boards involved. The schematic shows some of these boards twice to depicting the two channels separately.
The function switch and the input RCA terminals are on F-2569. Boards F-2571 and F2572, which have the tape play switches and a separate tuner on off switch, are soldered to F-2569 to form a cluster of three boards.
The function switch has positions for two phono inputs and two aux inputs. The tuner is selected with a separate toggle switch. It doesn't appear to matter what position the function switch is in, flipping the tuner switch appears to bypasses it. Can a problem with the tuner switch drag down the input signal?
- Pete
Has anyone run into this before? This is one complected input signal path. Before I take the function switch off the board and tear it apart, I want to make sure that the dropout is not being caused elsewhere in this complected signal path.
Here's a clip of the schematic.
There are three boards involved. The schematic shows some of these boards twice to depicting the two channels separately.
The function switch and the input RCA terminals are on F-2569. Boards F-2571 and F2572, which have the tape play switches and a separate tuner on off switch, are soldered to F-2569 to form a cluster of three boards.
The function switch has positions for two phono inputs and two aux inputs. The tuner is selected with a separate toggle switch. It doesn't appear to matter what position the function switch is in, flipping the tuner switch appears to bypasses it. Can a problem with the tuner switch drag down the input signal?
- Pete