• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Audio Amplifier 2.1 Broken

fred5959

New Member
Hello,
Is their somebody who can help me with this circuit , it is an audio amplifier unit 2.1.
I think the output must have short circuited, afterwards I was only getting the green on light from the switched power supply going on and off, making a clicking sound on the subwoofer.
After opening the case I probably between 2 pair off capacitors, I discovered 2 inductors (coils) without enough specification mark on, not sufficient to find a replacement.
A Crossover ?
I hope somebody here could help me wit this.
IMG_20191115_022153.jpgIMG_20191115_022209jpeg.jpgIMG_20191120_212513 jpeg.jpg
 
Last edited:

Ylli

Active Member
Those small inductor are part of the output filter network. The chance of them being bad is nil. Most likely, you fried one or more of the output devices. Post a bit more infomation, such as amplifier model number and output device part numbers.
 

fred5959

New Member
Sorry for the bit later reply. Its about a Trust Tytan loudspeakerset 2.2.1 . I must say the picture taken from the circuitboard IMG_20191120_212513 was still when their was nothing broke. I include the picture off the case where where the circuit is builded in.
I still can get the capacitors µF , i saw on one of the picture where the broken board is shown liquid leaked out of those 2 ??inductors or coils ,between the 4 capacitors but i didn't found what freq they have for replacement.
At least if they are broken.trust-tytan-21-speakerset-60w-zwart.jpg
 

Ylli

Active Member
Can we get a picture of the area where you see leakage? And can you read a part number on the 3 heat sink mounted parts?
 

fred5959

New Member
I've put the pictures a bit more clearer their. In the 2 above pictures you can clearly see the leak in the third picture is the same area seen but when this was still functional. you can see their marked on S 03 01 or 5 03 01
But for the 3 parts on the head sink I don't find any numberpart probably the endtransistors.
 

Ylli

Active Member
Is that 'leaked' area wet? If not, it isn't leakage, it is simply an adhesive they add to hold the parts. I can't find any info on that unit online.

Unless someone else has a different idea.... Can you get at the bottom of the board and take a picture? Trying to determine the lead outs of the amplifiers on the heat sink. How are your soldering skills? I think we will need to remove all three of the amplifier chips and then see if the power supply comes up. If it does, we can replace the amplifiers one at a time to try and figure out which one(s) are bad. Then we would need to figure out a replacement part.
 

RadioRon

Well-Known Member
The "leakage" looks to me like wax or similar substance intentionally put there at the factory to help stabilize the large capacitors. Those inductors are clearly labelled as Lxx so there is no question they are inductors. The positioning of those parts on the board imply they are part of the power supply filtering rather than output filtering.
I agree that since there is no obvious burned components visible, the next likely problem may be failed output ICs.
 

fred5959

New Member
Here i have to skip one, for the moment ,at this moment I have no soldering gun.
If it would have been a more simple task I could have asked someone to solder another part onto the circuit.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Here i have to skip one, for the moment ,at this moment I have no soldering gun.
Which is a good thing, as you're suspecting components which have pretty well zero chance of been faulty, as others have said it's most likely the output IC's that you've blown.

The 'leakage' is no such thing, it's simply adhesive used to hold the components in place during manufacture, and to help prevent dry joints occurring in the future.
 

Electro_Hero

New Member
The "leakage" looks like wax or glue to prevent the capacitors from fall off and oxidation. It is designed to be there, not the leakage of something.
 

unclejed613

Well-Known Member
Most Helpful Member
since the board in inside a speaker cabinet, the glue is used to keep heavy components like capacitors and inductors having their leads broken by metal fatigue (from vibration). those devices on the heat sink are the most likely cause if the problem. i'm betting one of them is shorted most likely from the output pin to one or both of the power supply rails.
 

Latest threads

EE World Online Articles

Loading

 
Top