Skip to main content

SOLVED: iPhone 6 board short circuit caused no display after boot

Most of the electronic products are afraid to fall, no matter how expensive it is. Okay, maybe Nokia won't. However, today we're going to talk about a case of a problem after the iPhone was dropped. This iPhone 6 was dropped to the ground, and the screen is broken. When turn it on, it shows black screen. When we connect it to DCpower supply, it shows large current. According this, we can know that it is short circuit. Now, we need to fix it.

First, disassemble the iPhone and energize the motherboard. The DC power supply displays 1.7V current that is short circuit and the adjustable power supply voltage is pulled down to 3.4V. The whole motherboard gets hot, especially the main power drive chip.

Second, deenergize it and measure the power supply of each circuit at motherboard through multimeter, find that the power supply of PP3V0_NAND of EEPROM is short circuit to ground and the resistance data is 0. The test points of PP3V0_NAND are shown in picture 1-1.

1-1

Third, use solder iron to make rosin in the capacitance which connect PP3V0-NAND, then slowly turn the current button of adjustable DC power supply to increase the current limit, the inductor that is connected with PP3V0_NAND melts when the current is 3A. Therefore, this inductor is short circuit. Deenergize it and remove this inductor, as shown in picture 1-2.

1-2

Fourth, after removing this inductor and plugging adjustable power supply, it is not short circuit. IPhone can get into IOS normally. Remove a inductor from the same place of the accessories pad to replace the old one. This problem was been solved.

Tips:


As this 3V voltage is parallelly connected many capacitors. It will take long to tear them one by one. Thus we use burn-in method to find the short circuit point. Put rosin on motherboard and set the adjustable power supply to 3V. Adjust the current limit to the lowest. Connect the negative pole of adjustable power supply to ground and connect the positive pole to the short circuit point. Then energize it. Slowly turn the current button of adjustable DC power supply to increase the current limit. The place that rosin melts fastest is faulty.
Labels:

Comments

Post a Comment

Popular posts from this blog

Complete Guide to Replacing Your iPhone Battery at Home

  Has your iPhone battery started showing the dreaded signs of age, like frequent charging, rapid draining, or even an untimely shutdown? Are you considering a battery replacement but feeling deterred by the potential cost or hassle of a trip to the Apple Store? Don't worry; with the right guidance, you can replace your iPhone battery at home quickly and safely, sparing your wallet and ensuring a future of longer charge cycles for your beloved device. Whether you have the latest model or an older version, we'll walk you through the process step by step. But before we get into the nitty-gritty, here's why a battery replacement might be in your best interest. Why You Should Replace Your iPhone Battery The lithium-ion batteries in our smartphones are not immortal. They degrade over time due to a variety of factors, such as age, temperature, and the number of charge cycles. Replacing an old battery can provide several benefits: Improved Performance: A new battery can result ...
Post a Comment
Read more

User Manual: JC V1 Programmer to fix iPhone light sensor/vibrator

As we know, the light sensor and vibrator is very important for iPhone screen. If you want to replace the iPhone screen, you also need to transfer the original screen data to the new iPhone screen(iPhone 8 to iPhone Xs Max),so you can make sure the new iPhone screen will work fine. Here is a  JC V1 programmer  to fix iPhone light sensor and vibrator problem (for iPhone 7- iPhone Xs Max), it also can repair iPhone baseband eeprom IC or iPhone logic eeprom IC problem. The JC V1 Programmer comes with 24-inch HD display screen, three-color LED indicator light, two small connecting seats (for connecting function panel) , two buttons and one function panel (including light sensor/touch connector, baseband function connector, vibration connector) It support 2 languages (Chinese/English) and three lines of code (read/write/burn/save), the function panel can be changed, the software can automatically update What’s the functions? - Repair iPhone Light sensor/ true ...
1 comment
Read more

Here: JC P11 iPhone Nand Test Fixture Specification Details

JC P11 iPhone Nand test fixture is on sale now, some users still confused for it, what's credit points for JC P11? Why it's cheap? As we know, JC P11 BGA110 programmer is the latest programmer for iPhone   iPhone XS Max,XS, X, 8P, 8  and iPhone 11 Pro max/pro/11, which is made by JCID factory.  Here are some  specification details for JC P11 programmer . 1. Main Functions. - Support to modify and write BGA110 NAND SYSCFG data (NAND Flash underlying data, such as SN/BT/WIFI and others); Unbind WIFI. - It doesn't require restoring the firmware for brand-new Nand flash, the SYSCFG data can be written directly. - Repair the Error 35 during firmware restoring for BGA110 NAND - Repair the DATA Error for BGA110 NAND - Support iPhone 8/8P/X/XS/XS Max currently, free software upgrade to support 11-11Pro Max in the future - Initiate the network charging mode, can purchase the points according to the demand, which greatly saves the equipmen...
Post a Comment
Read more