TDA7266 IC Faulty Causing No Sound In TV
A customer of mine sent to me this Singer Slim TV with the complaint of no sound but other features were all fine. Usually, if there is no sound in TV, the problem could be due to:
- Bad speakers
- Broken speaker cables
- Dry joints in the audio IC
- Improper or missing DC supply voltage the audio IC
- Faulty Audio IC
- Corrupted EEPROM data and etc
So in this case I checked on the speakers first since this is the most easiest component to check. I took out the speakers cables and checked and found that both have low and same resistance which means they are both good. If no readings means the speaker resistance is already open circuit. You can click here to read Yogesh ‘s post about checking TV speakers. Next, I tested the output audio jack using external speakers and there were no sound too.
The next test I performed was to measure the DC supply voltage to the audio IC TDA7266 and it showed 11.9 VDC which also means good-see the two photos below:
I left only one choice which is to direct replace the audio IC TDA7266 and retest the set. I had in stock this IC and replaced and retested the sound.
Surprisingly the sound came back after the IC replacement.
You can click on the IC datasheet below to view the complete information about this amplifier IC.
I was so happy that the sound came back to life and wish to let you listen to the TV sound. I could only captured the photo of a working TV -below photo:
Conclusion- Assuming if after the replacement of the IC and the TV still has no sound, the next test would be to check on the EEprom IC. You can click here to check on my previous post about faulty EEPROM IC that has caused no sound in TV. If you wants to be good in CRT TV repair you can check out Humphrey’s ebook Here.
This article was prepared for you by Suranga Bandara who owns an Electronics repair shop in Anuradapura, Sri Lanka.
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Note: You may check out his previous post in the below links:
https://jestineyong.com/16-33-v-5-47v-x-2-linear-transformer-fault/
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Albert van Bemmelen
September 4, 2018 at 9:14 pm
Good job! They might as well make these TDA Audio amplifier IC's Plug-And-Play with decent sockets in the rate they tend to fail and have to be replaced in lots of repairs.
Parasuraman S
September 4, 2018 at 9:20 pm
Excellent professional approach and solution!
Yogesh Panchal
September 5, 2018 at 12:47 am
Good Job! suranga
Henrique Jorge Guimarães Ulbrich
September 6, 2018 at 12:06 am
Good job, Suranga. And I agree with Albert about the need of decent sockets. However, this would bring about an increase of production costs, and the manufacturers don´t like this.
beh
September 6, 2018 at 10:59 am
Hi Suranga
Is very useful repair report like other ones.
thanks.
beh
Humberto
September 7, 2018 at 11:40 pm
Good repair Suranga.
Robert Calk Jr.
September 8, 2018 at 1:28 pm
Good job, Suranga.
Justice
September 13, 2018 at 8:15 pm
Very technical work above all interesting thank you Suranga.
Tyrone Arendse
September 14, 2018 at 12:48 am
Good explanation on how to troubleshoot
Hamisu
July 23, 2020 at 8:38 am
I check the DC volage to ic is normal and I test the IC is good. What going to be the problem help please.
umut
March 5, 2021 at 5:19 am
new TDA7266SA FAKE