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Released on September 19, 2014, this 4.7" screen iPhone is the smaller version of the iPhone 6 Plus. Identifiable by the model numbers A1549, A1586, and A1589.

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No power after baseband reball

Hi all, hoping for some inspiration from someone! Got an iPhone 6 which was working fine in every respect except it had the Searching/No Signal issue. No IMEI from #*06* and no Carrier entry in Settings, so I went ahead and removed the baseband ic to fit 2 jumpers. I got really good soldered points on the vias for the 2 jumpers and was pleased with the result; I then covered the area with green curable solder mask, cured it until rock hard, cleaned up the pads on the BGA and re-fitted the baseband chip. This all went fine, and when it was back on I tested all the caps in the vicinity for continuity and all were fine. However when I plugged it in it's drawing 0.00 amps . I tested both VCC-MAIN and BATT_VCC for shorts and the battery line was shorted. I then had a closer look around and found that one of the chips close to baseband (U_2GPARF) was looking a little crooked and may have moved while I was working there. I checked on PADS and found out that this ic has a direct connection from the battery connector, so I removed the ic, cleaned the pads, reballed the chip and put it back; BATT_VCC short gone. Plugged it back in - still 0.00A. Then I thought that as both Tristar and Tigris are right on back of the board from where I'd been working that the heat had maybe caused solder to flow and bridge or short, so changed both tristar and tigris. Plugged it back in , yep 0.00A! I'm beat now, I can't think of what else to try. I don't think baseband has any direct connections to power lines and that's all I did initially; and I'm not even sure that baseband is needed for boot anyway? Doesn't seem to be a power line issue and nothing is shorted or damaged etc. Anyone got any ideas of what I should try next?? Thanks

Beantwoord! View the answer Dit probleem heb ik ook

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have you got a dc power supply

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Hi yes I have a DCPS and will try that later. Before doing so I'm going to take off Q1403 as it has multiple VCC_MAIN and PP_BATT_VCC feeds. Maybe I'll bridge it and see if that has any effect. Other than that, possibly a hammer....

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i would try the power supply first to see if you have any heat build up etc

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q1403 could be possible since you worked on tigris

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hi george, did u find the problem? i have same problem here.. please help thanks

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I was about to answer this when I realized it dates back several months. By now I'm sure George figured it out but for anyone else who happens onto this question via search, here are some ideas to follow through on for a similar problem:

  • Check the baseband PMU, which is directly opposite of the Baseband CPU to insure that all of the outputs are working and not shorted. Excess heat on the baseband rework could cause this.
  • Check all of the IC's that have a connection to PP_BATT_VCC including the several RF IC's
  • Reball the Baseband CPU (as @tech_ni) suggested.

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thanks minho trying to help, i will try it tomorrow. =)

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Hi @ william22, If you found this answer helpful, please select "Was this answer helpful? - YES"

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George Wright zal eeuwig dankbaar zijn.
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