Category: Audio System Repair and Service
Contents of this article
- Troubleshooting
- Power supply circuit
HARMAN KARDON SB30 - SB230
Troubleshooting
The soundbar does not turn on (the Power LED is off):
The soundbar does not turn on (the Power LED is off):
# Check that the soundbar’s power cord is
plugged into a working AC outlet.
# Check that the soundbar’s Power switch is in the “On” position.
# Check if the soundbar’s AC fuse has blown. See Soundbar Rear-Panel Controls and Connections: AC Fuse Holder, on page 4, for instructions on checking and changing the fuse.
# Check if the soundbar’s voltage selector switch is set in the incorrect position for the AC voltage in your area.
# Check that the soundbar’s Power switch is in the “On” position.
# Check if the soundbar’s AC fuse has blown. See Soundbar Rear-Panel Controls and Connections: AC Fuse Holder, on page 4, for instructions on checking and changing the fuse.
# Check if the soundbar’s voltage selector switch is set in the incorrect position for the AC voltage in your area.
The subwoofer does not turn on (the Power LED is off):
# Check that the subwoofer’s power cord is
plugged into a working AC outlet.
# Check that the subwoofer’s Power switch is in the “On” position.
# Check that the subwoofer’s Power switch is in the “On” position.
There is no sound coming from both the soundbar and the subwoofer (their
Power LEDs are amber or blue):
# Check that the soundbar is on (the Power LED is blue).
# Check that the cable connecting the TV or other source component to the soundbar is properly connected at both ends.
# Check that the soundbar is set to the correct input source (one white Status
LED glows for optical digital, two white Status LEDs for coaxial digital, and three white Status LEDs for analog) and that the input source device is playing an audio signal.
# Check that the system is not muted (when the system is muted, the soundbar’s Power LED flashes blue). If the system is muted, press the remote control’s Mute button to un-mute the system.
# Check that the soundbar’s volume is not turned all the way down.
There is no sound coming from just the subwoofer (the Power LED is amber or blue):
# Check that the soundbar is on (the Power LED is blue).
# Check that the cable connecting the TV or other source component to the soundbar is properly connected at both ends.
# Check that the soundbar is set to the correct input source (one white Status
LED glows for optical digital, two white Status LEDs for coaxial digital, and three white Status LEDs for analog) and that the input source device is playing an audio signal.
# Check that the system is not muted (when the system is muted, the soundbar’s Power LED flashes blue). If the system is muted, press the remote control’s Mute button to un-mute the system.
# Check that the soundbar’s volume is not turned all the way down.
There is no sound coming from just the subwoofer (the Power LED is amber or blue):
# Check that the Subwoofer Volume control is
not turned all the way down (fully counterclockwise).
# Check that the Wireless Code switches on the subwoofer and soundbar are both set to the same setting number.
# Move the subwoofer closer to the soundbar. The maximum wireless operation distance is 50 feet (15.3m).
The soundbar’s sound is distorted:
# Check that the Wireless Code switches on the subwoofer and soundbar are both set to the same setting number.
# Move the subwoofer closer to the soundbar. The maximum wireless operation distance is 50 feet (15.3m).
The soundbar’s sound is distorted:
# Check the source device to see if the
distortion is coming from it and not from the soundbar.
The system’s sound is too quiet, even when the soundbar’s volume
is turned all the way up:
# If the TV or source component is connected via a variable analog output, check its
instructions to be sure that the output is not turned down too low.
The bass output is not loud enough:
# If the TV or source component is connected via a variable analog output, check its
instructions to be sure that the output is not turned down too low.
The bass output is not loud enough:
# Turn up the subwoofer’s Volume control.
# Move the subwoofer into a corner of the room.
# Move the subwoofer closer to the seating location.
# Move the subwoofer into a corner of the room.
# Move the subwoofer closer to the seating location.
L6599 High-voltage resonant
controller
Device description
The L6599 is a double-ended controller specific for the resonant half-bridge topology. It provides 50 % complementary duty cycle: the high-side switch and the low-side switch are driven ON\OFF 180° out-of-phase for exactly the same time. Output voltage regulation is obtained by modulating the operating frequency. A fixed deadtime inserted between the turn-OFF of one switch and the turn-ON of the other one guarantees soft-switching and enables high-frequency operation. To drive the high-side switch with the bootstrap approach, the IC incorporates a high-voltage floating structure able to withstand more than 600 V with a synchronous-driven high-voltage DMOS that replaces the external fast-recovery bootstrap diode. The IC enables the designer to set the operating frequency range of the converter by means of an externally programmable oscillator.
At start-up, to prevent uncontrolled inrush current, the switching frequency starts from a programmable maximum value and progressively decays until it reaches the steady-state value determined by the control loop. This frequency shift is non linear to minimize output voltage overshoots; its duration is programmable as well. The IC can be forced to enter a controlled burst-mode operation at light load, so as to keep converter's input consumption to a minimum.
IC's functions include a not-latched active-low disable input with current hysteresis useful for power sequencing or for brownout protection, a current sense input for OCP with frequency shift and delayed shutdown with automatic restart.
A higher level OCP latches off the IC if the first-level protection is not sufficient to control the primary current. Their combination offers complete protection against overload and short circuits. An additional latched disable input (DIS) allows easy implementation of OTP and/or OVP.
An interface with the PFC controller is provided that enables to switch off the pre-regulator during fault conditions, such as OCP shutdown and DIS high, or during burst-mode operation.
The L6599 is a double-ended controller specific for the resonant half-bridge topology. It provides 50 % complementary duty cycle: the high-side switch and the low-side switch are driven ON\OFF 180° out-of-phase for exactly the same time. Output voltage regulation is obtained by modulating the operating frequency. A fixed deadtime inserted between the turn-OFF of one switch and the turn-ON of the other one guarantees soft-switching and enables high-frequency operation. To drive the high-side switch with the bootstrap approach, the IC incorporates a high-voltage floating structure able to withstand more than 600 V with a synchronous-driven high-voltage DMOS that replaces the external fast-recovery bootstrap diode. The IC enables the designer to set the operating frequency range of the converter by means of an externally programmable oscillator.
At start-up, to prevent uncontrolled inrush current, the switching frequency starts from a programmable maximum value and progressively decays until it reaches the steady-state value determined by the control loop. This frequency shift is non linear to minimize output voltage overshoots; its duration is programmable as well. The IC can be forced to enter a controlled burst-mode operation at light load, so as to keep converter's input consumption to a minimum.
IC's functions include a not-latched active-low disable input with current hysteresis useful for power sequencing or for brownout protection, a current sense input for OCP with frequency shift and delayed shutdown with automatic restart.
A higher level OCP latches off the IC if the first-level protection is not sufficient to control the primary current. Their combination offers complete protection against overload and short circuits. An additional latched disable input (DIS) allows easy implementation of OTP and/or OVP.
An interface with the PFC controller is provided that enables to switch off the pre-regulator during fault conditions, such as OCP shutdown and DIS high, or during burst-mode operation.
Applications
# LCD and PDP TV
# Desktop PC, entry-level server
# Telecom SMPS
# AC-DC adapter, open frame SMPS
# LCD and PDP TV
# Desktop PC, entry-level server
# Telecom SMPS
# AC-DC adapter, open frame SMPS
POWER SUPPLY CIRCUIT
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