Announcement

Collapse
No announcement yet.

removing glued s/mount chips lg lb series

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

    removing glued s/mount chips lg lb series

    recently struggled to remove BL0202 backlight chip
    which had red residue of glue underneath
    as well as annoying laquer over the top and surrounding area.
    i had to use more heat than i like to remove it
    which can cause bubbling of the bcb
    i used two different types of flux,but it was the glue causing the problem .
    just wondered if anyone has had this problem ,and if there is any solvent that may loosen the glue before desoldering?
    (some vestel fets are also glued the same way)
    this was on a LG47 LB585V,
    I had replaced the led strips which were badly discoloured only to find q806 mdhd 4n20y s/c
    r840 burnt
    and bl0202b s/c

    #2
    Re: removing glued s/mount chips lg lb series

    Cut the legs of with a knife, remove the chip, then desolder the rest of the legs on the pads.

    Comment


      #3
      Re: removing glued s/mount chips lg lb series

      thanks at least someone reads my posts
      thats a good idea
      but when salvaging a chip from a scrap board obvious wont work
      so any thaughts on solvent to loosen the bond ?
      this repair has caused me grief as the availibility of MDHT4N20Y fet
      i could order from china but waiting 2 months is the problem
      even the chip BL0202B are scarce in uk

      Comment


        #4
        Re: removing glued s/mount chips lg lb series

        Plenty of people read the posts, photos always help get a response.
        I'm guessing the red glue is adhesive not underfil so a bit of heat and one of the BGA blades to cut it.
        I'm not sure where you're ordering from but my stuff takes around 2 weeks from Aliexpress.

        Comment


          #5
          Re: removing glued s/mount chips lg lb series

          philips use the red glue, you just heat the chip with hot air till the solder melts - then twist it with tweezers and the glue breaks.
          it's weakened by the heat

          Comment


            #6
            Re: removing glued s/mount chips lg lb series

            Originally posted by stj View Post
            philips use the red glue, you just heat the chip with hot air till the solder melts - then twist it with tweezers and the glue breaks.
            it's weakened by the heat
            what max temp would you suggest ? i normally use 250 degrees
            i had to turn up to max to budge it which is not good for the pcb

            Comment


              #7
              Re: removing glued s/mount chips lg lb series

              Originally posted by diif View Post
              Plenty of people read the posts, photos always help get a response.
              I'm guessing the red glue is adhesive not underfil so a bit of heat and one of the BGA blades to cut it.
              I'm not sure where you're ordering from but my stuff takes around 2 weeks from Aliexpress.
              i must just be unlucky
              aliexpress varies so much with del times
              and quality of product is sometimes poor

              Comment


                #8
                Re: removing glued s/mount chips lg lb series

                Originally posted by jimbofz View Post
                i must just be unlucky
                aliexpress varies so much with del times
                and quality of product is sometimes poor
                When you order on Aliexpress the cheapest option of postage is always the longest. You can select a quicker speed of postage more expensive that gets delivery within a couple of weeks.
                It is not intuitive to select the higher postage costs but it's generally available on all listings, as I recall you use a dropdown menu to select different options within your basket. Look and use sellers by the quantity of the orders and there feedback of the quality of the goods. Don't just buy product only on the basis of the price, which I am guessing you have done previously. You may pay a little extra but at least you will get it quicker and better quality.

                Comment


                  #9
                  Re: removing glued s/mount chips lg lb series

                  heat needs to be 300-350 really

                  as for ali, dont use "super cainiao" shipping, stick with ali standard or saver

                  Comment


                    #10
                    Re: removing glued s/mount chips lg lb series

                    Originally posted by stj View Post
                    heat needs to be 300-350 really

                    as for ali, dont use "super cainiao" shipping, stick with ali standard or saver
                    ive always tried to remove s/m components with the minimum temp
                    and then increase temp if the item is stubborn
                    and use the smallest nozzle on my s station
                    to prevent other close components flying off .
                    i will try 300-350 thanks

                    Comment


                      #11
                      Re: removing glued s/mount chips lg lb series

                      Originally posted by cheeky2 View Post
                      When you order on Aliexpress the cheapest option of postage is always the longest. You can select a quicker speed of postage more expensive that gets delivery within a couple of weeks.
                      It is not intuitive to select the higher postage costs but it's generally available on all listings, as I recall you use a dropdown menu to select different options within your basket. Look and use sellers by the quantity of the orders and there feedback of the quality of the goods. Don't just buy product only on the basis of the price, which I am guessing you have done previously. You may pay a little extra but at least you will get it quicker and better quality.
                      thanks thats good advice
                      i will follow it on next order

                      Comment

                      Working...
                      X