Need help! LED bulbs are blinking.

Discussion in 'General Electronics Chat' started by Platinum Imports Inc, Mar 8, 2013.

  1. Platinum Imports Inc

    Thread Starter New Member

    Mar 8, 2013
    4
    0
    Hi,
    I need some help here. I am new to the LED world, so I would like to know more about them if possible. I have some LED bulbs ( PAR 20) that are blinking when switched on and after about 5-10 seconds they go dim (very dim).
    The bulbs are rated for AC 90-265v.
    Can some tell me if it could be a problem with the bulb? or the power source?
    Please help out!!:

    Platinum.
     
  2. Kingsparks

    Member

    May 17, 2011
    118
    5
    Just a wild guess but I would say power source. If it were the LEDs I would think they would be out completely. Electronics can do strange things though so without more information that's the best I can do.

    If you have anything on them, post it please.

    Take care.
    Roland
     
  3. Platinum Imports Inc

    Thread Starter New Member

    Mar 8, 2013
    4
    0
    I just opened up one and it looks burnt on the circuit board. I attached the picture. would that be from voltage exceeding the max voltage rating?

    Thanks for your help so far.

    Platinum
     
  4. Kingsparks

    Member

    May 17, 2011
    118
    5
    Hard to say, but not likely unless it went out due to a storm or a surge of some sort. The board looks fried but I can't zoom in enough to see much so again, just a guess.

    How old is it and where is it located?

    Take care.
    Roland
     
    Last edited: Mar 8, 2013
  5. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
    463
    Not much to see here, take a macro with only the PCB, both sides.

    Did you use it outdoor/indoor, what kind of power supply? Regular grid? Any large loads switching on?
     
    Kingsparks likes this.
  6. Kingsparks

    Member

    May 17, 2011
    118
    5
    Thanks tako, I though I posted a second reply asking for a better photo but I must have punched the wrong button, no show.

    Roland
     
  7. Platinum Imports Inc

    Thread Starter New Member

    Mar 8, 2013
    4
    0
    Sorry forgot to upload the pictures..:)

    See attached picture's.
    They were in a hotel building, (I have 12 that are like this). I haven't checked the actual voltage of the building as yet but the service guy there told me it is 120v. (50Hz) ( I will go and check that myself )
    I believe they would be large loads switching on there.
    Let me know what other info you need.

    Thanks for help so far.

    Platinum.
     
  8. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
    463
    What to say? Either the LED or the board are toast or both.

    Leaves 3 possibilities.
     
  9. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,363
    Get rid of the blinking cheap LEDs.
     
  10. Evil Lurker

    Member

    Aug 25, 2011
    117
    23
    Looks sorta like you may have got hit with "conductive glue syndrome". See it quite a bit on some computer power supplies. What happens is they use this cheap glue, that after enough time and heat exposure has passed, it turns conductive. Who knows what all got shot but it does look like D2, or the second SMD M7 diode (which is basically the SMD equivalent of your typical 1N4007 through hole diode) is toast. I'm also gonna guess that the primary electrolytic cap is shot too, even though I can't see it having vented I bet the ESR is way up there. There is also the possibility that the (again guessing looks about the right size can't see the last number) 13005 transistor (Q1) is damaged too.
     
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