Always discharge the main filter capacitors (those two large 4700uF or 10,000uF cylinders) before sticking your probe in. The RX 4000 stores enough voltage to bite back—even when unplugged. Do you have a burnt resistor in your RX 4000 and can't read the color code? Leave the component number (e.g., R117 or D203) in the comments below, and we will cross-reference it with the master schematic database.
However, like all high-performance electronics, the RX 4000 is susceptible to failure—especially when pushed to its limits. When the smoke escapes or the protection light flashes, the most vital tool for any technician is the (often referred to as the schematic or service manual). nx audio rx 4000 circuit diagram
| | What it looks like on the real RX 4000 PCB | | :--- | :--- | | Ground Symbol | Large copper pour, usually around the mounting holes and RCA shields. | | Vcc (+15V) | Thin red trace or a bus wire running to the preamp section (8-pin ICs). | | Output Transistors | Large TO-247 or TO-264 packages screwed to the center heatsink. | | Zobel Network | A 10 Ohm resistor and a 100nF capacitor connected directly to the speaker output terminal. (Stops oscillation). | Always discharge the main filter capacitors (those two