Tda2030 2.1 amp noise problem

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JMFahey

JMFahey

Member
Joined 2009
STILL WORRIED

1) WHAT does PE mean???
Show PE on a picture.

2) Where are you touching your probes to?
Red to: ------
Black to: -----

3)
it shows high voltage that is dangerous to touch with bare hand
Click to expand...
An that voltage would be??????
Please state how many Volts and if AC or DC

4) get a neon screwdriver and check it does not light when touching heatsink, supply ground, +/- supply points, etc.

How to Use a ScrewDriver Neon Tester - Easy Way! - YouTube
Only the first 38 seconds apply (how to use it), do NOT open or disassemble it by any means.
 
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N

Neon128

Member
Joined 2021
diyMartin said:
Hi
No problem - that is why I rephrased my question.
What do you mean by "PE"? - I am afraid that I still dont understand what voltage you have measured.


But let me try this from a different angle:
It is a little bit unprecise to assess the circuit by the two pictures of the assembled board - but if I get it right, the AC input (12Vac - 0 - 12Vac) from the transformer is connected such that the 0 - the middle pin in the 3-pin connector - from the transformer is connected to amplifier ground.
This is where you have soldered the black wire.{yes}


When measuring the voltage on the heatsink, then measure the voltage between the 0 on the transformer (also called the center tap) and the heatsink - with and without the short between ground and the heatsink.{haven't measured the voltage on the heatsink relative to the centertap without the black wire connected to ground, but with connected the voltage is 0vdc}
Use the DC-setting on your multimeter and tell us what voltage you measure.{0vdc}
The second of above measurements should give you 0V - otherwise you are not measuring where I explain.


Then measure - using the AC-setting on your multimeter - the voltage from 0 to the two 12VAC connections and tell us what you measure.


All of above is only to understand why you seem to have measured more than 36V anywhere in this amplifier - because as NareshBrd explains thisshould not happen for that chip amplifier.{ well i got a shock and then measured over 36vac on the heatsink relative to the earth terminal of our house, this was after I had isolated the chips and heatsink and grounded it}


Next - using the ohm-range on the multimeter: WITHOUT POWER connected measure the resistance from the small cooling fin on each amplifier chip to the heatsink.
There seems to be proper isolation in between - but this step is to ensure that the isolation actually works.{ checked isolated nicely}


Third: Look at the solder joint on pin 3 on the middle TDA2030 - from the picture it looks faulty.{ checked its good too}


Fourth: If you have access to an oscilloscope - then tell us. That will make the next steps easier. {still dreaming of owning an oscilloscope}


Cheers,
Martin
Click to expand...
 
N

Neon128

Member
Joined 2021
JMFahey said:
STILL WORRIED

1) WHAT does PE mean??? {protective earth terminal}
Show PE on a picture.

2) Where are you touching your probes to?
Red to: ------ {heatsink}
Black to: ----- {earth terminal}

3)
An that voltage would be??????{over 36vac}
Please state how many Volts and if AC or DC

4) get a neon screwdriver and check it does not light when touching heatsink, supply ground, +/- supply points, etc.{ahh the neon screwdriver lights up when touching the grounded heatsink}

How to Use a ScrewDriver Neon Tester - Easy Way! - YouTube
Only the first 38 seconds apply (how to use it), do NOT open or disassemble it by any means.
Click to expand...
 
A

Alexchoi

Member
Joined 2009
I have this 2.1 amp in stock, I like to share,
in the photo, the copper side of the board appeared to be not so ideal.
if de-solder the bad joints and re-solder them would be a big help.

if you have capacitors in stock, it is more ideal to change them.

the tab of the ICs are connected to their pin3 , they should be isolated from the heatsink.

the heatsink is better connect to ground,
the heatsink should not have -volts, if -v appeared on the heatsink, it is the isolation sheets of the ICs could not isolate the tabs (-v) from the heatsink.

around +18v and -18v should be there ref to center point of the two capacitors. ( ground ) +18v to pin5, -18v to pin3 of the ICs.

you can check the rectifiers with your multimeter, (diode mode)
and check the resistors ..
check the ac connector for good connections, ( two ac 12v ).

the hum could be coursed by bad joints.

its just a suggestion.
hope you fix it soon.
 
A

Alexchoi

Member
Joined 2009
correction: insulation replace isolation.

I have this 2.1 amp in stock, I like to share,
in the photo, the copper side of the board appeared to be not so ideal.
if de-solder the bad joints and re-solder them would be a big help.

if you have capacitors in stock, it is more ideal to change them.

the tab of the ICs are connected to their pin3 , they should be insulated from the heatsink.

the heatsink is better connect to ground,
the heatsink should not have -volts, if -v appeared on the heatsink, it is the insulation pads of the ICs could not insulate the tabs (-v) from the heatsink.

around +18v and -18v should be there ref to center point of the two capacitors. ( ground ) +18v to pin5, -18v to pin3 of the ICs.

you can check the rectifiers with your multimeter, (diode mode)
and check the resistors ..
check the ac connector for good connections, ( two ac 12v ).

the hum could be coursed by bad joints.

its just a suggestion.
hope you fix it soon.

sorry for wrong spelling.
 
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N

Neon128

Member
Joined 2021
Alexchoi said:
I have this 2.1 amp in stock, I like to share,
in the photo, the copper side of the board appeared to be not so ideal.
if de-solder the bad joints and re-solder them would be a big help.

if you have capacitors in stock, it is more ideal to change them.

the tab of the ICs are connected to their pin3 , they should be isolated from the heatsink.

the heatsink is better connect to ground,
the heatsink should not have -volts, if -v appeared on the heatsink, it is the isolation sheets of the ICs could not isolate the tabs (-v) from the heatsink.

around +18v and -18v should be there ref to center point of the two capacitors. ( ground ) +18v to pin5, -18v to pin3 of the ICs.

you can check the rectifiers with your multimeter, (diode mode)
and check the resistors ..
check the ac connector for good connections, ( two ac 12v ).

the hum could be coursed by bad joints.

its just a suggestion.
hope you fix it soon.
Click to expand...

I've already checked all of these and it still has jitter noise
 
N

Neon128

Member
Joined 2021
Well it isn't a humming noise as in low frequency, it is a high frequency jitter from the two satellite speakers, I changed the tda2030 chips with better quality ones and even that didn't work, the only way the jitter would go away is when we touched the heatsink when it was connected to negative 12vdc through the chips middle leg, question is what change occurred when we touched the heatsink/negative 12vdc? Something to do with radio interference? EMI? Something else?
 
N

NareshBrd

Member
Joined 2017
Check your circuit against this
Also connect the heat sink through a 100 ohms or so resistor to mains earth and see what happens.
The 4558 ic filters out high frequency to the woofer, so the high frequencies are given to the satellite speakers only....
 

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Stream

Stream

Member
Joined 2008
s3am.livejournal.com
Neon128 said:
I was trying to avoid having to check the whole circuit as it is not worth the time, so in the meantime I'll just have to move on to a better amplifier
Click to expand...
Too sad you didn’t answer on all asked questions from people, who tried to help you.
Next time try to follow recommendations and suggestions and reply with numbers and pics, and not just “it was ok”, or “there was high voltage”. This way you will save your time and time if people, who tries to help you.
 
N

Neon128

Member
Joined 2021
@stream Well if you see i did tried to reply with number and picture not just " it was ok " but as i mentioned before i am new with this Forum type things so might messed up or didn’t reply to few which is unexpected and i deeply Apologise for that. Everyone tried to help has my utmost respect for taking their time and thinking about it. So you might wonder why i am postponing it after asking for help the reason is its around 2usd circuit which i was testing if this cheap circuits actually works so what i was looking for if someone faced similar situation about that noise. The last suggestion i think was checking the whole circuit, i am sure you know checking the whole circuit is very time consuming which is why i have to do it later. For your kind information i am very much amateur with electronics, my first language is not English and i am new to this so maybe misunderstood things or didn’t reply properly that my fault i would like to again apologise to those who actually tried to help and thought about this problem. usually you would see in fb people saying random unnecessary stuff in comments but that doesn’t happen here so thats great! Looking forward learn for you all. And definitely will reply if i can solve the problem of that circuit.
 
A

Alexchoi

Member
Joined 2009
I compared the image in #3 with my board,
I found the only difference is in the ground pad layout,

mine ground begin with the center joint of the 2 big caps ,
all along from that center joint to the TDA2030s,
then to the filtering IC,
finally to the input jack ground.

I found this board,
the input ground is in the mid way of the subwoofer ground.
this could cause instability.


I thought if try to connect two wires from the center joint of 2 big caps,
one to the SW ground joint,
the other to the input ground joint, this mod might be helpful.
(if this mod works then isolate the input ground pin from the ground pad)

its just a suggestion
 
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