Announcement

Collapse
No announcement yet.

faulty loudspeaker amplifier-no sound output

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    faulty loudspeaker amplifier-no sound output

    I've several amplifiers of different sizes which are faulty. I haven't fixed them because I haven't a clue. This is the smallest culprit. 240v in (UK) and 12v dc to the board. Small neon lights when power button is on. Different dc voltages across all of the capacitors. Where do I go from here?

    #2
    How do you delete photo's once published. 2 I've just uploaded are better.
    Attached Files

    Comment


      #3
      Click image for larger version

Name:	C8C7620B-C8C6-43D0-970D-5EA7371CF476.png
Views:	101
Size:	750.7 KB
ID:	3259905 Hi, look at the diagram Click image for larger version  Name:	96139538-B210-4B06-98CC-51F00079EE06.png Views:	0 Size:	636.7 KB ID:	3259901
      Last edited by kasfamily; 04-25-2024, 11:52 AM.

      Comment


        #4
        Thanks for the diagram. Did you just work out the schematic by looking at my photos? You are really clever if you did. I'll work thro and let you know how I get on.

        Comment


          #5
          You think too well of me, these are just standard amplifier circuits on this chip.

          Comment


            #6
            I've checked all components and haven't found any faulty ones. I've pull the capacitors and their within 10% of stated values. Ic checks. Pin 1 is 7v Pin 2 is 16v pin 3 is 7v. Would you expect to see voltages on pin 1 and 3 which are the speaker outputs?
            How do you manage to check the traces against the drawing? Turning the board over everytime to check the component impossible.

            Comment


              #7
              Hi,
              The maximum supply voltage is 15 V in the datasheet. On pins 1 and 3 -7V this is normal. On pins 5 and 8 - 0.5 V is normal.
              Try to trace the connections to the lumen with a lamp Click image for larger version

Name:	95D9BE6D-BE13-4D50-B8E8-79B739FA98BE.jpg
Views:	75
Size:	2.09 MB
ID:	3265410
              Last edited by kasfamily; 05-05-2024, 11:59 AM.

              Comment


                #8
                Thanks for your advice. I've tried my bench magnifier but I'll try a fluorescent light for a brighter view. If all the tracks check out with a multimeter I guess I'll have to go for the last option of scrapping what could be a perfectly good tda 2822 chip and soldering in a replacement. I haven't got one so will have to order one.

                Comment

                Working...
                X