thread top ad

Collapse

Announcement

Collapse

READ BEFORE REGISTERING SO YOUR ACCOUNT WORKS

In order for your account to be activated INSTANTLY, your PayPal email MUST MATCH THE EMAIL YOU USE TO REGISTER YOUR ACCOUNT ON THIS FORUM!! If your PAYPAL email address differs from your FORUM email address, your account will have to be activated MANUALLY when a customer service agent gets around to it.

I realize this sucks, and I do apologize.
See more
See less

820-2879 green light, not turning on and not charging

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

  • #16
    I replaced the ISL6259 from a donor board and it is still fluctuating as I said previously. I also put flux and heated the SMC to rid of any corrosion under it and that still didn't solve this. Pins 17/18 27/28 resistance and traces are fine.
    Any other ideas dukefawks 2informaticos ? I may have to refund the customer and send this back.
    Last edited by ytesfay80; 03-22-2017, 05:26 AM.

    Comment


    • #17
      Check resistance to ground at L6995, in 200k scale.
      Remove Q7221 and tell us voltages at L7220/60 when PPBUS_G3H is high.

      Comment


      • #18
        Red probe on Pin 1 of L6995 black on ground in resistance mode 200k scale shows 280kohms.
        I removed Q7221 and measured.
        L7220 was showing nothing but pulses of 0.05-0.13v.
        L7260 was showing no voltage at all.

        L7220 in diode mode was 0v to ground on both sides.
        L7260 was 0.43v to ground on both sides.

        Also now I am seeing 3.38v on Pin of R7273 where before I was getting 0v on it.

        Should I remove L7220 and see which side the short is on?
        Last edited by ytesfay80; 03-22-2017, 03:50 PM.

        Comment


        • #19
          I'm wondering how can you read 280 value in a 200 scale...
          You've probably used auto-range, not 200K selected.

          Lift one pin of L7220 and look where the short is.
          Be aware, this will not completely discard TPS!
          Inject voltage starting with 1V, maybe less; keep the current under the limit of your lab supply.

          The short appeared when you powered up the board without TPS; don't do that again...

          Comment


          • #20
            I removed L7220. Pin 1 was showing 0.002v and Pin 2 was showing 0.07v in diode mode so I went to resistance mode to ground and Pin 2 was OL and Pin 1 was like 5ohms so I injected 1v into Pin 1 and couldn't feel anything getting warm so I went slowly up towards 2v(shows 2amps going through) and the only thing I feel getting warm is U1400 and the opposite side of the board where u1400 is. I put alcohol on those areas and nothing burned away unusually fast.
            Last edited by ytesfay80; 03-22-2017, 08:48 PM.

            Comment


            • #21
              Okay I removed the thermal paste from the U1400 chip and confirmed that it is getting really hot when I put 2.6v on the PP3v3_s5 line.

              That means the chip would need to be replaced to fix this right?

              Comment


              • #22
                Good luck to find a new MCP.
                Is probably better to trash this board...
                It still has more issues; not charging is not related with MCP.

                Comment


                • #23
                  Okay thanks.

                  Comment

                  thread bottom ad

                  Collapse
                  Working...
                  X