Announcement

Collapse

Announcement

Welcome to the NEW iPad Rehab Forum! Everyone is welcome to read posts and learn for free. If you'd like to post your own question on the forum, please click "register" above or go here: http://forum.mendonipadrehab.com/register to enroll as a paid subscriber for $29/mo for unlimited access to our forum support and private signature failure section.
See more
See less

iphone 6 Plus Touch IC not working after replaceing meson+M1J and Cumulus

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

  • iphone 6 Plus Touch IC not working after replaceing meson+M1J and Cumulus

    iphone 6 plus
    Came in with touch ic evidence, touch partially working, replaced screen touch still faulty but working partially
    replaced meson 3 times with jumper, replaced cumulus 2 times , checked digitizer fpc and fpc is well soldered, took diode mode readings and matches known good readings, visual inspection over caps and other components around meson and look fine.
    Dont' kbnow where to go from here

  • #2
    I think we can say meson and cumulus are both fine lol. I'd check the schemetic and see what other components the two ics require. I know from experience those big orange inductors can get damaged.

    Comment


    • #3
      you replaced meson three times.....and you still have partial touch? or you have no touch now?

      Comment


      • #4
        Phone: iPhone 6 Plus
        Board: 820-3675-A

        Hi, I've started the repair of 6+ as usual M1 jumper, phone has not been opened before. After job done, I've still got touch, but M1 didn't solve the sync problem (still had unresponsive touch after flexing but I think that grey bars disappeared). Removed Meson, installed L1 jumper too, still didn't solve the problem.

        When removing black gunk on elements under J1111 connector (because i was scared that i will reflow the components underneath), i've botched up one element, and then while replacing the one that fell off moved some more, so i had few incidents I've replaced all fallen components from doner board. After stitching up, the phone worked and touch worked..

        Replaced CUMULUS, no joy. Then I don't know exactly when the touch stopped responding, but now I'm not getting any touch at all. I'm sneaking around the cumulus VDDANA that has 1.502 V and VDDCORE @1.478V. I've replaced Cumulus and Meson a couple of times with NEW chips.
        But it seems that's nothing wrong with the IC-s. I've measured the resistance between VDDANA and VDDCORE with CUMULUS ON and OFF the board, and it's in Mohms region, same result when measuring both rails to ground.

        All input voltages seem to be OK. PP1V8_GRAPE = 1.799 V, PP5v1_GRAPE_VDDH = 5.113V
        Last edited by BlackCore; 06-13-2018, 05:34 PM.

        Comment


        • #5
          You might have put to much heat on chestnut while doing the touch ic's.

          Comment


          • #6
            I had the exact same problem about a week or so ago and it ended up being a bad connection under chestnut. Once I heated it up with some flux under it and gave it a bump, touch started working and customer has not had to come back since

            Comment


            • #7
              You are right to question your touch voltages. But you need to consider ALL voltages required for touch. What powers meson?

              Comment


              • #8
                Phone: iPhone 6 Plus
                Board: 820-3675-A

                Here is an update:

                I've got the touch working again, it seems that there was a problem with the FPC connector, have replaced it and now have found out that the other side (connector on the LCD) is also not in such good shape, and it's still behaving when flexing the board. I will address that this probably is the main problem that when I put the phone into the housing and when trying to bend the housing stronger it loses touch.

                There is a lot of things that can get wrong, especially when you remove black gunk around elements besides connector. Be really careful when prying the connectors from the board, as the components underneath are much more vulnerable. I've knocked off the 255k (indeed measures 1.2 Mohm IDK why), that is on the OIC_RIGHT_NET. This has to be responsible in some manner to the right side of the touch as it was unresponsive...

                I've noticed when the board is out of the housing when I press in on the meson and cumulus the icon that it's press and dragged on the screen starts to jitter. So I guess that there is somewhere a bad contact or lack of good continuity that makes touch inaccurate..

                Also, my theory of bad connection on FPC seems to be confirmed because if I connect the known good LCD with nice and snug FPC on it, it works flawlessly.


                Originally posted by Jessa_the_Professa View Post
                You are right to question your touch voltages. But you need to consider ALL voltages required for touch. What powers meson?
                Thanks, Jessa the Professa for pointing this out.

                I think you mean voltages from CHESTNUT(PN5V7_SAGE_AVDDN, PP5V7_SAGE_AVDDH from NUT and PP1V8).Yeah, they are OK. It seems that I didn't damaged my NUT

                Comment

                Working...
                X