My Circuit Problem

Discussion in 'The Projects Forum' started by khushal1988, Dec 12, 2010.

  1. khushal1988

    Thread Starter Member

    Nov 12, 2010
    70
    0
    i attached the picture of my circuit , in dis circuit it was working fine but after i changed my IC IR2111 , of channel1 now the MOSFET IR540N of channel 2 named as Q2 it becomes hot and my system is not working i changed every thing i thought may be something is burnt or not functioning but no success so i request please go through the ciruit and then the picture of circuit and identify the problem or make me a layout for the circuit so i can get my system back as i m going to present demo of my project tomorow morning :-( please help me out.
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    How about labeling those chips? I'm not to good at guessing part numbers and functions.
     
  3. khushal1988

    Thread Starter Member

    Nov 12, 2010
    70
    0
    please see the attachments :)
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    Can you post a picture with good focus, but more lighting of both sides of the board?

    What is the exact function of the board?

    Has it ever worked? If so, when did it stop working? Why did you change the IC out?
     
  5. khushal1988

    Thread Starter Member

    Nov 12, 2010
    70
    0
    the function of the board is it runs ultrasonic transducer and make them audible for human ears , and it stoped working some days before 3 or 4 days when i removed ir2111 ic and replaced other nd with soldergun i did smthing after that its not working an 1 of it IRF540 MOSFET becomes red hot :-( while others are cold with no output now it was working fine i have imported from japan from the website zao.jp/rado in there parametric speaker :-(
     
    • 1.JPG
      1.JPG
      File size:
      280.2 KB
      Views:
      31
    • 2.jpg
      2.jpg
      File size:
      262.3 KB
      Views:
      31
    • 3.JPG
      3.JPG
      File size:
      284.7 KB
      Views:
      23
  6. iONic

    AAC Fanatic!

    Nov 16, 2007
    1,420
    68
    You really need more light, much more! This will help with the blurry photos as well if you do not have a tripod.
     
  7. khushal1988

    Thread Starter Member

    Nov 12, 2010
    70
    0
    it cant be more :-(
     
  8. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,670
    804
    What about daylight? Even on a cloudy day it is still far more light than anything inside.
     
  9. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    Flashlights will also work.

    Did you take these pictures?
     
  10. indianhits

    Active Member

    Jul 25, 2009
    86
    0
    ok you rounded the IC and said its overheating then why can't you use heat sink
     
  11. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Outside on a cloudy/overcast day provides nearly ideal lighting for taking such photographs.

    Solder guns are not good to use for circuit boards; it is far too easy to fry components and burn traces.

    You should use a soldering iron rated at around 20w-40w. It's better to use a temperature-controlled iron.

    I prefer Sn63/Pb37 solder (63% tin, 37% lead), however it can be hard to find nowadays. 60/40 solder works OK.

    You must clean your board and components using isopropyl or denatured alcohol before trying to solder them, and you should have a clean and tinned iron.

    Good solder joints look bright and shiny like silver, and the solder looks "wet" even after it has cooled. If you are trying to solder dirty connections, you may need to use rosin flux. You will need to clean the flux residue off after the solder cools using isopropyl alcohol.

    Some of your soldering looks pretty bad, but it's hard to tell with the poor quality of the photos that you have posted.
     
  12. khushal1988

    Thread Starter Member

    Nov 12, 2010
    70
    0
    these attachments may visible properly now :)
     
  13. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    What are the extra jumper wires for?

    The soldering work needs some improvement. Watch This Video

    You want to be sure you heat both the pad and the component lead at the same time, so solder flows through the layers. I looks like you have many cold solder joints on the board, with an excess of solder on the bottom side, and many places where it didn't flow through to the top layer.
     
  14. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Given that the schematic in this thread is identical to the one here - http://forum.allaboutcircuits.com/showthread.php?t=46846 , it is odd that so much fuss and feathers got raised about making a PCB in that other thread - the OP has a functioning (or at one time, functioning) PCB in his possession, as is clearly indicated in this thread.

    Could the OP explain what is going on? Have you messed up the current board and need a reverse engineered replacement. The very strange traces in the partial layout in the other thread makes no sense, as there was a functional board to act as a guide.
     
  15. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    Thanks for the link beenthere, I didn't connect the two schematics until now.

    Is the OP using a board that was "kinda close" to what he wanted and modifying it?

    *sigh*
     
  16. iONic

    AAC Fanatic!

    Nov 16, 2007
    1,420
    68
    I saw and I Just shut my mouth!
     
  17. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    Obviously OP needs better soldering skills. With that experience I doubt he can solder a new one
     
Loading...