JBL DA850 DA1650 Owners Manual | rev1.2 Draft20231009
Pg 15 of 16
©2023 Harman International | Features, Specifications, and Appearance subject to change without notice.
Troubleshooting and Maintenance
Troubleshooting
The amplifier does not power on.
1. Attempt to power on the amplifier with the front panel Standby/On button.
2. Examine the power cord to ensure a good connection between the rear panel AC input connector and the wall
outlet.
3. Check the wall outlet.
The Trigger Input is connected to an external device, but the amplifier does not power on and
off with the external device.
1. Verify the trigger cable is connected at both ends and verify that the trigger cable is connected to the right
device. Also re-verify the trigger installation as instructed in the Hardware Setup section of this user guide.
2. Verify the trigger level of the output source device. The DA accepts a range of 4.5-15VDC.
Source signals are present and the system is at a suitable volume level but one or more channels
are not passing audio.
1. Reduce system volume level.
2. Power the DA into standby mode.
3. Check
input
connections.
4. Check speaker connections.
5. Allow the amplifier to cool before powering it on again.
Audio sounds “thin” and is lacking proper bass response.
Check to ensure proper polarity of the speaker cables and connections.
Audio Levels differ between zones.
1. Check the level settings of the DA Output Level Controls.
2. Check the settings on your preamp, processor or controller.
Audio plays and then cuts off.
Check input and speaker connections for short circuits or loose connections at the amplifier and speaker.
A humming sound is present in the audio.
Audible hum, or a discernable low frequency noise is one of the most common problems within audio/video
systems. This problem, even when the volume is at a low level, is usually caused by a common problem known as
a “ground loop”. A ground loop occurs when there is a difference in ground voltages between two or more
components that are connected electrically. In most cases, one or more of the following suggestions below will
solve the hum problem.
1. Disconnect components one at a time to isolate the problem. Once the problem is identified, make sure the
associated component is properly grounded and connected to the same electrical ground as the DA amplifier.
2. Turn off all components within your system and then disconnect the input cables on the DA amplifier. Turn the
amplifier back on. If the hum disappears the fault may be with the input cables that are being used. Make sure
the cables are properly shielded or use a cable that has better shielding. Make sure the cable is not running or
laying on top of any AC power cords.
3.
Ground loop problems may also be caused by poor grounding of the electrical system within your home or may
be caused by faulty earth grounds in your home’s electrical system. To isolate the problem, try unplugging
components with three prong grounded power cords one at a time to see if one or all are causing the problem.
Please check with a licensed electrician for further evaluation.
If all else fails…
1. Contact an authorized JBL dealer.
2.
Contact JBL Customer Technical Support
Maintenance
Routine maintenance should be performed on a periodic basis. Clean the exterior surfaces of the unit with a soft, dry,
lint-free cloth. Do not use alcohol, benzene, acetone-based cleaners, or strong commercial cleaners. Do not use a
cloth made with steel wool or metal polish. If the unit is exposed to a dusty environment, a low-pressure blower may
be used to remove dust from its exterior.
