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Remote Control - The Right Way To Fix It

Discussion in 'Troubleshooting and Repair' started by itai shi, Apr 27, 2016.

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  1. itai shi

    itai shi

    18
    3
    Apr 22, 2016
    hi everyone,
    (hope i am in the right section with that unsolved issue)

    the issue : Fixing a faulty Remote Control.

    i have a remote control of a DVB-T (Hyundai HY-2806), that suddenly had stopped functioning.

    the right steps to check it (as for my opinion) :
    1. Replace to Remote batteries for a new pairs - still not functioning.
    2. i brought a same remote model from someone, tried it , and its work perfect
    conclustion: - the DVB-T is ok, the Remote is faulty.
    3. remote's LED output check:
    put the remote in front of a camera (The LED towards the camera)
    now press some buttons on the remote,
    if on the camera we see the remote's LED lights on and off, so the remote is somehow functioning.
    if no lights seen on the camera, so the remote is completely dead - this is my case.
    4. i openned the remote and solder again all the solders on the PCB ,
    put back all the parts, and tried again - still nothing.
    5. now i am on a dead end:
    on the PCB, only 3 chips/parts :
    a. the LED
    b. a chip called HS 455E (is it a kind of oscillator?)

    [​IMG] Ceramic resonator HS455E

    c. the "Brain" or CPU, dont know how to name it , and it is hiding under a black , inflexiable big dot.
    is there way to know what under it?

    any suggestions of what else can be done?

    remote3.PNG remote4.PNG remote1.png

    thanks,
    itai.
     
  2. KJ6EAD

    KJ6EAD

    1,114
    158
    Aug 13, 2011
    The blob is called a COB (chip on board). It is unrepairable.
     
    itai shi likes this.
  3. Alec_t

    Alec_t

    2,909
    791
    Jul 7, 2015
    You've shown that there is no IR emission. Try measuring the voltage across the IR LED (preferably using an oscilloscope, but a DMM will probably suffice). If it changes when you press any button on the remote then that suggests a dead LED.
     
  4. Colin Mitchell

    Colin Mitchell

    1,417
    313
    Aug 31, 2014
    This is from an electronics expert:

    "Try measuring the voltage across the IR LED (preferably using an oscilloscope, but a DMM will probably suffice). If it changes when you press any button on the remote then that suggests a dead LED."
     
    Last edited by a moderator: Apr 27, 2016
  5. davenn

    davenn Moderator

    13,710
    1,911
    Sep 5, 2009
    its a crystal (filter) that is used in an oscillator in the IC under the black blob as part of the oscillator circuit
    They quite often go faulty .. getting damaged when the remote is dropped on the floor
     
  6. 73's de Edd

    73's de Edd

    2,990
    1,261
    Aug 21, 2015
    .



    Sir itai shi. . . . . . .


    Mac Guyver procedure:

    After going the routes suggested above . . . .you can see if the 455 kHZ ceramic resonator is interfacing with your COB, by use of a small AM radio.
    That small sizing will let you get the internal loop antenna of the pocket radio belly to belly / back to back or butt to butt to the remotes COB.
    Turn the radio on and tune it OFF of any station at the 550 end of the AM band at MAXIMUM volume setting, Close couple . . . .vewy, vewy closely . . . . as mentioned above, and expect a fast data stream burst to be heard from the radio speaker when you press any Hyundai remote button.
    Different punched keys will alter that sound a bit . . . . . on a select few remotes . . . . holding down a up down volume or up down channel will emit a continual / repetitive tone stream.

    Passing the above test is designating that the 455 resonator operation with the COB is fine and a digital stream is getting put out.

    There is a high probability that the IR emitter LED is using Kovar leads . . . . Kovar . . . Kovar . . .what's a Kovar ? (Bring a STRONG neob-dimin-i-ninny-yum-yum magnet up to a LED lead and you will see.)

    They have a high proclivity of rejecting their overlay coating medium . . . . particularly in quick wave soldering operations .

    If CLOSE visual inspection does not confirm a floating wire lead(s) within the solder blobs, try wedging a fine sewing needles point within the solder blob to LED lead joint and press the remote button to see if it activates the Hyundai. Repeat the wedge with the other solder blob-LED lead.

    That's about all that comes to mind if not being batteries or one of the two battery to actual PCB connection problems.




    73's de Edd



    .
     
    Last edited: Apr 28, 2016
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