I made a bluetooth speaker with the TDA7492P red amplifier board.
But since yesterdag i have no sound anymore from the board.
I think i made a short between the speaker connections.
Can somebody tell if this short destroys the board?
And if it will only a componenent which one can it be, so i can replace the component.
bluetooth is stil working, and also the power led.
Hope someone can help
But since yesterdag i have no sound anymore from the board.
I think i made a short between the speaker connections.
Can somebody tell if this short destroys the board?
And if it will only a componenent which one can it be, so i can replace the component.
bluetooth is stil working, and also the power led.
Hope someone can help
The short circuit may have destroyed the TDA7492 chip. Perhaps not the current itself (there is probably an over current protection) but voltage spikes generated by the filter coils.
First the 10 Ohm test: No power supply or input signal. With an Ohm-meter in the 20K range. Looking at the two power terminals ("+" and "-") and the four speaker output terminals. If you measure between any (two) of these six terminals, do you get an Ohm-meter reading of less than 10 Ohm?
IF you have a combination with less than 10 Ohm, the chip is very likely defect, if not, it may still be defect.
If both channels are dead, it is not likely to be any other component than the TDA7492 because any other component would affect only one of the two stereo channels.
First the 10 Ohm test: No power supply or input signal. With an Ohm-meter in the 20K range. Looking at the two power terminals ("+" and "-") and the four speaker output terminals. If you measure between any (two) of these six terminals, do you get an Ohm-meter reading of less than 10 Ohm?
IF you have a combination with less than 10 Ohm, the chip is very likely defect, if not, it may still be defect.
If both channels are dead, it is not likely to be any other component than the TDA7492 because any other component would affect only one of the two stereo channels.
The easiest fix is a new pcb.
The TDA7294 are a pig to unsolder and replace unless holes are large.
You can cut all the pins high up then de-solder them holding the top of the pin with long nose pliers gently pull on pin while heating with iron.
None of the output terminals have less than 10 Ohm to supply "+" or "-"?
Next step is the use of an oscilloscope and check the signal on each pin of the TDA7492. If it is not to learn about the TDA7492, it is easier just to buy another board.
It is possible to replace a TDA7492 chip (even SMD) if you are experienced with soldering. But, you need to get another chip and a new board is not that much more expensive.
Next step is the use of an oscilloscope and check the signal on each pin of the TDA7492. If it is not to learn about the TDA7492, it is easier just to buy another board.
It is possible to replace a TDA7492 chip (even SMD) if you are experienced with soldering. But, you need to get another chip and a new board is not that much more expensive.
Today i received a new board from china.
After i connected the speakers to the board. i smell something terrible. a saw smoke from the speaker.
Ohno not again.
It is the right channel that is wrong.
I measure a voltage of 12V on the right channel.
the left channel is only 0.03 volt
who knows what is wrong and how can i fix this?
After i connected the speakers to the board. i smell something terrible. a saw smoke from the speaker.
Ohno not again.
It is the right channel that is wrong.
I measure a voltage of 12V on the right channel.
the left channel is only 0.03 volt
who knows what is wrong and how can i fix this?
I measured the voltage again.
When there is no bluetooth connection is measure on both channels 0.01 volt
with buetooth connection and music playing i measure on the left channel 0.03 volt
and on the right channel 19 volt
my power source is 19 volt.
I tried several times to switch on and off the bluetooth connection, and everytime when i have connectione there is 19 volt on the right channel.
I also measure the resistance between the + power connector and the + speaker connector.
with bluetooth off there is no resistance (open loop)
and with bluetooth on there is resistance (closed loop)
does somebody know what the problem may be?
and is there somewhere a schematic of this board?
When there is no bluetooth connection is measure on both channels 0.01 volt
with buetooth connection and music playing i measure on the left channel 0.03 volt
and on the right channel 19 volt
my power source is 19 volt.
I tried several times to switch on and off the bluetooth connection, and everytime when i have connectione there is 19 volt on the right channel.
I also measure the resistance between the + power connector and the + speaker connector.
with bluetooth off there is no resistance (open loop)
and with bluetooth on there is resistance (closed loop)
does somebody know what the problem may be?
and is there somewhere a schematic of this board?
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I don't know where i can find the bluetooth audio out and amplifier in on the board.
But it is a standard board, i should be working.
I have now two board this board is exect the same as the other one, and that one was working wel, til i made a short.
I have tried the board also with a 12v power supply, and then there is only 4v on the speaker out.
I also tested the bluetooth again, but it looks like there is only an high voltage when the music is playing, and not when there is a bluetooth connection
But it is a standard board, i should be working.
I have now two board this board is exect the same as the other one, and that one was working wel, til i made a short.
I have tried the board also with a 12v power supply, and then there is only 4v on the speaker out.
I also tested the bluetooth again, but it looks like there is only an high voltage when the music is playing, and not when there is a bluetooth connection
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No, both boards didn't have the same issue.
The first board i made a mistake, i shortend the speaker outputs. after that the board didn't work anymore.
I ordered a new board, it arrived today. I hooked up the speakers black wire on the - red wire on the +
made bluetooth connection, the right speaker begun to smake and smell terrible.
That is what happend and nothing more.
The youtube video is not the problem i have.
I have a big voltage on the right channel when playing music, which cause to blow up the right speaker.
The first board i made a mistake, i shortend the speaker outputs. after that the board didn't work anymore.
I ordered a new board, it arrived today. I hooked up the speakers black wire on the - red wire on the +
made bluetooth connection, the right speaker begun to smake and smell terrible.
That is what happend and nothing more.
The youtube video is not the problem i have.
I have a big voltage on the right channel when playing music, which cause to blow up the right speaker.
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You are not lucky with your boards.
My experience is that even a short lasting short-circuit of the output pins may damage the class D chip permanently. Therefore, try to make your last purchase work for a start.
The TDA7492 is supposed to work down to 8V so use a 12V supply until it seems to work. There is no need to provide more energy to destroy your amplifier as long as the amplifier appears to be defect.
Connect two 8Ohm dummy loads to the outputs, connect your 12V supply to the DC-plug and turn the power on:
Do all four 330uF/35V decoupling capacitors have 12V across them?
Without any Bluetooth connection, what is the DC voltage measured across each of the two dummy loads?
Do the DC output voltages across the two dummy loads change when you connect to the Bluetooth receiver and starts playing music?
NB: NEVER use your good speakers for a start when you test a new amplifier. In case of doubt, use dummy resistors. In case of confidence, use some cheap test speakers until you are sure that the amplifier works correctly.
My experience is that even a short lasting short-circuit of the output pins may damage the class D chip permanently. Therefore, try to make your last purchase work for a start.
The TDA7492 is supposed to work down to 8V so use a 12V supply until it seems to work. There is no need to provide more energy to destroy your amplifier as long as the amplifier appears to be defect.
Connect two 8Ohm dummy loads to the outputs, connect your 12V supply to the DC-plug and turn the power on:
Do all four 330uF/35V decoupling capacitors have 12V across them?
Without any Bluetooth connection, what is the DC voltage measured across each of the two dummy loads?
Do the DC output voltages across the two dummy loads change when you connect to the Bluetooth receiver and starts playing music?
NB: NEVER use your good speakers for a start when you test a new amplifier. In case of doubt, use dummy resistors. In case of confidence, use some cheap test speakers until you are sure that the amplifier works correctly.
i put on each channel a 8 ohm resistor
And attached a 12v power supply
all four capacitors do have 12v across them.
i measure on the right channel 0.007 volt and the left 0.017 volt
when bluetooth connects i didn't have time to measure but is looks like it is more than 6 volt on the right channel, the risistor begins immidiatly to burn
I know it was stupid
And attached a 12v power supply
all four capacitors do have 12v across them.
i measure on the right channel 0.007 volt and the left 0.017 volt
when bluetooth connects i didn't have time to measure but is looks like it is more than 6 volt on the right channel, the risistor begins immidiatly to burn
I know it was stupid
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