Sharp CRT TV No Sound
My friend text me that her crt tv which was manufactured by sharp corporation. The model no. 14v 8 and the next number or letter is already erased because the tv is has an aged of 5 to 8 yrs. She told that the sound was not coming anymore. But before it was happened you can hear some low sound until it came to no sound at all.
So i came to her place and and i saw the tv and i test it, confirm no sound. So i open the back cover and look direct to audio circuit or section and i saw a monolithic audio IC which is TDA7056A. At first i dont know itwas a mono audio IC and the first impression to me it is stereo type or dual audio IC because it has two speakes on both side of the tv. I first check on some electrolytic cap that surround the IC because mostly it is the culprit and i replaced two caps. I try to power the tv and still no sound coming oooh i told to myself. I unplugged the tv again and drain the main filter capacitor so that it is safe to troubleshoot again again the board of the tv.
I check the two speakers and one of them is open coil. It is 8 ohms and 15 watts if im not mistaken. So i ask myself if the IC is okay one of the speaker must have audio. So i suspect the IC is faulty to my conclusion. But before i finally change the IC, I resoldered all pins of the TDA7056A and the surrounding components but unlucky. So i put the a new IC to my surprised still no sound at all, this time the speaker that are good is only one the right side if you are at the back of tv, because the other one is open.. So i am puzzled what happen supposed i should hear the sound but none. I was so embarrassed to myself. and im thinking to surrender to troubleshoot. But i saw a speaker of a component in the house which they are renting and i told to her can i borrowed the one speaker. She told me Yes. To my surprised when i connect the speaker from inside the house ( note: the other speaker is already attached at the board and this two will function) the sound begin to come and i was amazed to what happen. Because this is the first time i encounter that problem. So i conclude that the IC i replaced is good and i need two speaker to switch the monolithic ic to produced a sound.So i buy a new speaker and put it and connect it to the board. And the owner my friend was happy and i learned a new lesson. Share your experienced if you have one like this..
This the picture of the IC TDA7056A.
.jpg)
The Data and schematic diagram and its pin out.
So i came to her place and and i saw the tv and i test it, confirm no sound. So i open the back cover and look direct to audio circuit or section and i saw a monolithic audio IC which is TDA7056A. At first i dont know itwas a mono audio IC and the first impression to me it is stereo type or dual audio IC because it has two speakes on both side of the tv. I first check on some electrolytic cap that surround the IC because mostly it is the culprit and i replaced two caps. I try to power the tv and still no sound coming oooh i told to myself. I unplugged the tv again and drain the main filter capacitor so that it is safe to troubleshoot again again the board of the tv.
I check the two speakers and one of them is open coil. It is 8 ohms and 15 watts if im not mistaken. So i ask myself if the IC is okay one of the speaker must have audio. So i suspect the IC is faulty to my conclusion. But before i finally change the IC, I resoldered all pins of the TDA7056A and the surrounding components but unlucky. So i put the a new IC to my surprised still no sound at all, this time the speaker that are good is only one the right side if you are at the back of tv, because the other one is open.. So i am puzzled what happen supposed i should hear the sound but none. I was so embarrassed to myself. and im thinking to surrender to troubleshoot. But i saw a speaker of a component in the house which they are renting and i told to her can i borrowed the one speaker. She told me Yes. To my surprised when i connect the speaker from inside the house ( note: the other speaker is already attached at the board and this two will function) the sound begin to come and i was amazed to what happen. Because this is the first time i encounter that problem. So i conclude that the IC i replaced is good and i need two speaker to switch the monolithic ic to produced a sound.So i buy a new speaker and put it and connect it to the board. And the owner my friend was happy and i learned a new lesson. Share your experienced if you have one like this..
This the picture of the IC TDA7056A.
.jpg)
The Data and schematic diagram and its pin out.
posted by zed at
January 10, 2013
1 Comments
