Sunday, December 22, 2013

JBL JSR-400 Dolby Pro-Logic Audio/Video Surround Receiver _ TROUBLESHOOTING

TROUBLESHOOT
If there is no sound from any of the speakers, check the following:
Make sure the receiver is plugged into an active AC wall outlet.
Push “Speakers” button on the receiver.
Make sure there is a source – for example, a VCR or television – hooked up to the VCR or tape/aux input jacks on the receiver.
Make sure that the program material is playing.
Recheck the hookup connections.

If most of the sound comes from the center-channel with little or no information from the surround channels, note the following:
Although most of today’s televisions are equipped with stereo audio output jacks, some stereo televisions have poor audio sections and are unable to provide a Dolby speaker, Pro Logic encoded signal. In the unlikely event that you experience this problem, connecting the audio outputs from your Hi-Fi VCR, laser disc player, DVD player or satellite receiver directly to one of the inputs on the receiver will provide a proper audio signal and allow you to enjoy true Dolby Pro Logic surround sound.

If there is no sound from the surround speakers or it is very low, check the following
Check all connections between amplifier and each of the speakers.
Raise the surround volume from the remote control.
Make sure the TV show or movie you are watching is recorded in Dolby Surround.
Make sure Dolby Pro Logic is engaged.

If there is no sound from the center speaker, check the Following
Make sure that the processor is in the Pro Logic, or 3 Stereo mode. If it is in Phantom or Stereo mode, the center speaker will not play.
Check the connections between the receiver and the center speaker.

If you are having trouble picking up radio stations, check the following:
Make sure the antenna is hooked up properly.
Depending on your distance from the station’s transmitter, you may need to install an FM antenna on the roof or in the attic.

Receiver inoperative
Faulty AC power cord. (FL indicator does not light) Replace.
Defective power switch. Replace.
Broken wire in the power transformer. Replace the power transformer.
Blown fuse. Replace the fuse.

Fuse blows when power is turned on.
Defective power transformer. Replace.
Short on the primary or secondary of the transformer circuitry. Repair the short.
Damaged rectifier (D20) or damaged “transistor (Q3, Q11, Q12).” Replace the defective component/s.
Short circuit in the amplifier circuit. Replace the shorted component/s in the amplifier circuit.

FL indicator lights but no sound
Defect in IC3 on the Main Board. from both channels.  Replace the defective component/s.

One channel does not work when volume is at maximum with a test Signal applied to the center terminal of volume control VR1 of The dead channel.
“Defect in IC2,IC3 on the Main Board” signal applied to the center terminal volume is at maximum with a test channel. Locate and correct the defect.
Break in copper foil of printed circuit board. Repair the trace.
Short in speaker output terminal. Repair or replace.

Speaker works normally but Headphones inoperative.
Headphone plug does not mate with jack. Replace the jack.
“Defective resistor R52, R53.” Replace.

FM inoperative
Defective front-end. (PACK1) Replace.
Defective FM switch. Replace the switch.
“Defective transistors Q1,Q2,Q3,Q201,” “Q202 or IC2, IC3, IC4" Replace the defective transistor(s) or IC(s).
Defective coil T4. Replace the coil(s).
Defective lead-in. Repair or replace the lead-in.
“Ceramic filters F101, F102 defective.” Replace the defective ceramic filter(s).
Defective controller circuit component. Replace.

Poor multiplex separation
Improper adjustment. Readjust VR401.
IC4 defective. Replace.
Variable resistor VR401 defective. Replace the variable resistor.

STEREO indicator does not light.
Defective indicator in FL. Replace.
Defective IC4. Replace the defective component.

FM volume not sufficient.
If volume from both L and R channels is not loud enough: Front end section defective. “Faulty IC3, Coil T4" Defective C412 on Tuner Board. If sound of one
channel is not loud enough: “Defective Q401, Q402"

AM inoperative A) Damaged IC3 of tuner board. Replace.
“Defective T1, T2, T6 or F202 of ” Tuner Board. Replace the defective component(s).
“Resistors R301, R302 defective.” Replace the defective component(s).
“Capacitors C438, C322, C412 defective.” Replace the defective capacitor(s).
Defective AM switch. Replace.
“Defective varicap diodes VC1, VC2.” Replace varicap diode(s).
Damaged AM loop antenna. Repair or replace.
Defective controller circuit component. Replace.

Bass control has no effect.
Variable resistor BASS defective. Replace.
“Defective R60, R63, C47, C48, C52, C53" Replace the defective component(s).

Treble control has no effect.
Variable resistor TREBLE defective. Replace
“Defective R70, R73, R77, R79, ” “C58, C61, C63, C64.” Replace the defective component(s).

Auto tune inoperative. (UP/DOWN)
Poor contact on Up/Down key. Repair or replace.
Defective IC on Front Board. Replace.
Defective tuner circuit components. Replace.
“In case of FM only, improper adjustment” of FM front-end. Readjust.

Manual tune inoperative. (UP/DOWN)
Poor contact in Up/Down key. (AM or FM) Replace.
Defective IC1 on Front Board. Replace.

Memory setting (Keys 1-10) inoperative.
Poor contact on memory keys 1-10. Replace
Poor contact on memory set key. Replace.
Defective IC1 on Front Board. Replace the defective component.

FL inoperative.
FL defective. Replace.
Defective IC1 on Front Board. Replace.

Noisy volume control.
Defective volume control. Replace.
“Defective capacitors C1, C2.” Replace the defective capacitor(s).
Remote Control Unit inoperative.
Weak battery. Replace.
Defective. Replace.
Defective IC1 on Front Board. Replace.