True, it is not that the carrier changes in amplitude with change of the audio level. Without an output filter we loose some control of the loading of the chip. This is why I suggest not to load the chip too much in the audio range without an output filter. For testing if the chip works this is very useful, not for trying out the limits of the chip.
Hi Zoran,
I had to do some cleaning this morning. I'm ready now.
If you remove all chokes (such that you will have no sound on any output), connect your 12V/1A supply and measure the supply voltage on the supply terminals (supposed to be 12V), do you have stable 12V readings on your voltmeter or are the readings going down every 2-3 seconds?
I had to do some cleaning this morning. I'm ready now.
If you remove all chokes (such that you will have no sound on any output), connect your 12V/1A supply and measure the supply voltage on the supply terminals (supposed to be 12V), do you have stable 12V readings on your voltmeter or are the readings going down every 2-3 seconds?
I found your board in more versions:
TPA3116D2 50Wx2 100W 2.1 canal sonore amplificateur numerique 12 24V DC XH M139-in Amplificateur from Electronique on AliExpress
XH M573 TPA3116D2 80 W + 80 W + 100 W 2.1 canaux TPA3116 carte amplificateur de puissance numerique basse Subwoofer hifi amplificateurs B2 002-in Amplificateur from Electronique on AliExpress
AIYIMA Bluetooth 5.0 TPA3116D2 amplificateur de puissance numerique carte Audio 50Wx2 + 100W 2.1 son haut parleur amplificateur Subwoofer AUX Mini ampli on AliExpress
TPA3116 carte amplificateur numerique haute puissance TPA3116D2 Audio DC12V 26V 2*80W + 100W Subwoofer amplificateurs sonores 2.1 pour haut parleur bricolage-in Amplificateur from Electronique on AliExpress
As you can see, your board uses chokes with yellow cores, the other boards chokes with black cores.
I have chokes with black cores as well and they function at 400KHz.
TPA3116D2 50Wx2 100W 2.1 canal sonore amplificateur numerique 12 24V DC XH M139-in Amplificateur from Electronique on AliExpress
XH M573 TPA3116D2 80 W + 80 W + 100 W 2.1 canaux TPA3116 carte amplificateur de puissance numerique basse Subwoofer hifi amplificateurs B2 002-in Amplificateur from Electronique on AliExpress
AIYIMA Bluetooth 5.0 TPA3116D2 amplificateur de puissance numerique carte Audio 50Wx2 + 100W 2.1 son haut parleur amplificateur Subwoofer AUX Mini ampli on AliExpress
TPA3116 carte amplificateur numerique haute puissance TPA3116D2 Audio DC12V 26V 2*80W + 100W Subwoofer amplificateurs sonores 2.1 pour haut parleur bricolage-in Amplificateur from Electronique on AliExpress
As you can see, your board uses chokes with yellow cores, the other boards chokes with black cores.
I have chokes with black cores as well and they function at 400KHz.
Thanks for testing.
The sudden voltage drops hints that at moments strong currents are drawn somewhere.
With all chokes removed it cannot be strong currents running to the outputs. It is likely that strong currents are drawn inside at least one of the TPA3116 chips. That should not happen.
Time for the chip test: NO POWER, use your Ohm-meter only. Ohm-meter setting 2Kohm. The "+" and "-" power supply terminals you find on the small blue terminal block close to the black DC-plug.
The board has 6 lines coming from one of the two TPA3116 chips and going to the input terminal PCB-pads used for the chokes we just removed. Measure the impedance from any of these choke terminal PCB-pads and first to the power supply "+" terminal, then to the power supply "-" terminal. Do any of these 12 measurements give you less than 100 Ohm?
Zoran, I believe you are right.
The 6 chokes are likely to need replacement. At least one of the TPA3116 chips may be defect. Buying replacement parts may bring you close to the price for a new similar board (that should work) but you still have to do the repair work and risk that something is still not good.
Thanks for letting the forum members know about your problems. Only by knowing about such problems other can avoid buying defective versions. Personally, I just received a good looking TDA8954 board (NXPs best chip) just to realize that it also had issues that needed to be solved before it would work.
I hope that this bad experience has not scared you from DIY in the future. Use the forum (and eventually YouTube) to get opinions about a board before buying.
FF
Many thanks Jonathan, very much appreciated.
Also I learn a lot from being forced to think about how things really relate and how to explain it to others in an understandable way.
If one TPA3116 amplifier chip is defect, it is possible to remove that chip and the other chip should work again. The last test I proposed aimed at finding out if one TPA3116 chip is defect.
If it is your sub-channel that is defect, the stereo channel may play on. If it is the stereo channel that is defect, the sub-channel on its own is less fun (mono and mainly bass).
A problem is that you measured 2K on all pins but there are still high currents running so we do still not know where the defect is.
On 6 volts the amp which still has gain set for 24volts will start clipping with almost no input. Check the Fualt pin... I'll bet it's bouncing on and off like crazy.
Without having a diagram to show: for each of the four TPA3116 output lines, a Schottky diode to the positive supply rail and Schottky diode to the negative supply rail. Diode anode to the negative supply rail and diode cathode to the positive supply rail.
Thank you very much! Could not imagine that was as simple as that, I was wondering where to fit 8 diodes on that small board. Already burst 2 TPA3118 boards.