my jbl bar 500 just stopped turning on, no lights, nothing. it was working yesterday.

Diagnosis

The JBL Bar 500 is experiencing a "No Power" state, which is typically caused by a failure in the AC-DC conversion stage of the internal power supply unit (PSU). When there are no LED indicators on the front panel and the unit fails to respond to both the remote and physical buttons, the circuit is broken. This is often triggered by a voltage spike or a "brownout" that trips the internal protection circuitry or blows the primary fuse on the power board to prevent the main processor from frying.

Another common root cause is a failure in the power brick or the internal capacitor bank. If the unit was working yesterday, it is likely that a capacitor has leaked or a MOSFET has shorted out during the shutdown process. To confirm this is a power failure and not a software "freeze," check if the subwoofer is still receiving power; if the subwoofer LED is on but the bar is dead, the issue is isolated specifically to the soundbar's internal power board rather than the wall outlet.

How to Fix It

Follow these precise steps to perform a hard hardware reset and isolate the power failure:

1. Disconnect the power cable from the back of the JBL Bar 500 and unplug the cable from the wall outlet.
2. Locate the subwoofer and unplug it from its power source as well. This ensures no residual current is looping through the wireless link.
3. Wait exactly 180 seconds (3 minutes). This allows the internal capacitors on the power board to fully discharge, which can clear a "latched" protection state.
4. Plug the soundbar directly into a known-working wall outlet. Do not use a surge protector, power strip, or extension cord for this test, as these can either be faulty or provide insufficient amperage to "kickstart" a stalled PSU.
5. Press and hold the Power button on the top/side of the soundbar chassis for 5-10 seconds. Do not use the remote control, as the IR receiver may be unresponsive during a power failure.
6. If the LED light flashes or turns on, immediately plug the subwoofer back in and attempt to pair.

If That Didn't Work

• Inspect the Power Cable: Check the AC cord for any kinks, frays, or chew marks from pets. Swap the power cable with a compatible C7 "figure-8" cable if you have one from another device (like a PlayStation or a printer) to rule out a cable break.
• Perform a Factory Reset: While the unit is plugged in, press and hold the "Volume +" and "Source" buttons simultaneously for 10 seconds. Even if the lights are off, this can sometimes force the firmware to reboot and trigger the power-on sequence.
• Check for "Sleep Mode" Lock: Occasionally, the Bar 500 enters a deep sleep mode that ignores the remote. Try pressing the "Wake" or "Power" button on the physical unit multiple times in rapid succession to trigger the internal relay.
• Voltage Testing: If you have a multimeter, test the wall outlet to ensure it is delivering the correct voltage (110V-240V depending on your region). A tripped circuit breaker in your home may be providing "ghost voltage" that isn't enough to power the unit.

Heads Up

• Avoid plugging the Bar 500 into high-voltage appliances (like a refrigerator or microwave) on the same circuit to prevent surge-induced PSU failure.
• Ensure the soundbar is placed in a well-ventilated area; overheating the internal power board can lead to permanent capacitor failure.
• Never attempt to open the chassis to replace the internal fuse unless you are trained in electronics, as the capacitors can hold a lethal charge even when unplugged.
• Always use a high-quality surge protector once you have confirmed the unit works, as the Bar 500 is sensitive to grid fluctuations.