At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.
Check for either an open resistor in the B+ line that feeds the audio amp IC or remove the IC and check for B+. If the IC is shorted, the B+ reading will read low.
Dan
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
If you've replaced the LM4766 ICs and the humming sound returned, there could be a few possibilities to consider:
Grounding Issues: Humming sounds in audio systems can often be caused by grounding issues. Ensure that all components are properly grounded and that there are no loose or disconnected grounding connections.
Power Supply Problems: The rapid loud hum could be related to power supply issues. Make sure the power supply is stable and within the correct voltage range. Also, check for any issues with the power cables or connections.
Filter Capacitors: Check the filter capacitors in the power supply section and around the LM4766 ICs. Faulty or aging capacitors can lead to noise issues in audio systems.
Signal Interference: Electrical interference from other devices or cables can sometimes cause humming sounds. Make sure the audio cables are properly shielded and not running too close to power cables.
Speaker Connections: Double-check all speaker connections, ensuring they are secure and properly connected. Loose or damaged speaker wires can lead to noise issues.
Board-Level Problems: There could be other components on the circuit board that are causing the issue. Inspect the circuit board for any signs of damage, burn marks, or soldering issues.
Magnetic Interference: Make sure there are no strong magnetic fields or sources of interference near the system that could be causing the humming sound.
Professional Help: If you've exhausted your troubleshooting efforts and the issue persists, it might be best to seek the assistance of a professional audio technician who has experience with Bose systems. They can perform more advanced diagnostics and repairs.
Remember that working with electronics and audio equipment requires technical expertise and can involve risks, including electrical hazards. If you're not comfortable or experienced with electronic repairs, it's advisable to seek professional assistance to avoid potential damage to the equipment or harm to yourself.
hi rohan, which ic is it?? sound ic? power supply ic? control ic? preamp ic? tuner ic? plz send more specific details? plz send picture of the ic placed in circuit?
The audio output Ic inside your tv has damaged, or it doesn't get proper voltage. You just open your TV, and locate the audio output Ic. It can be located by following the speaker wires. Usually it will be screwed onto a heatsink. Check the input voltage with the help of a multi meter, af it is there, the Ic is damaged. Replacing it will solve the problem. If there is no voltage, follow the supply track and find out the opened circuit point. Usually a small value resistor, say 0.01Ohms in value, will be connected in series with the power supply to Ic. If it gets opened, there will be no supply to Ic, resulting no sound. If the audio outpu Ic get short this resistor will open. So keep in mind that, if this resistor is opened, there may be a short inside the output Ic, or come capacitors fitted with this supply line, after the reistor. Check the also for any short. keep a keen look at the solderings fo the leges of this output Ic. Some loose, or bad solderings also may be there. Anyway, your TVs audio output section is faulty. Find the reason and rectify it. If audio Ic is found defective, desolder it out from the board, and replace it with a same type and number. Ok
the lack of sound is likely due to a defective audio output amplifier integrated circuit or IC for short, it needs replacing, the wavy lines through you picture is due to a defective filter capacitor in your power supply circuit, or may be due to the audio amplifier I.C drawing more current from your power supply causing a non clean power to be supplied to the video circuits, have the audio amp replaced first and note if the wavy lines are still present if so it is likely that some filter capacitors need replacing, to obtain sound you might be able to connect a external amplifier like your home stereo using the aux input and the sound output from your TV`s RCA jacks, this works well, let me know if you need further assistance good luck
If the picture is available and no sound, the trouble could be from speaker audio power supply or Audio IC. Check all the audio components. Check the sound mute status before replacing IC
DIsconnect sound Amplifier ic (RSN).After removal of the ic if the unit works o.k offcourse without sound than replace ic.If still f61 than sound ic is o.k and check voltege regulators in power supply.You can check dc detect line if it gets activated.
F61 is mainly two resons 1st sound ic or power supply problem in power bord which send signal to system control to shut down the power in order not to damege more.
philips 27PT54 no sound...perfect picture what happened?
×