iPhone 6s motherboard short after replace u2 ic
Sorry for my bad English
iphone 6s motherboard short after replace u2 ic. Then i remove u2 ic but still short is there, anyone can help me
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It would help if you told us which voltage rail is shorted.
What led you to believe that U2/Tristar was the problem?
When dealing with a “dead” phone, you have to start at the beginning and check PP_BATT_VCC, PP_VCC_MAIN and PP5V0_USB. I would start by checking to see if those rails are shorted to ground. If one of these rails is shorted to ground, then you will need to identify what is causing the short. It could be a bad decoupling capacitor, conductive debris or defective IC that is directly supplied by those rails.
Then you move onto the PMIC and check the voltage rails it generates:
- The PMIC generates ~15 voltage rails. They are all important (for obvious reasons) but the ones to check first are as follows: PP_CPU, PP_GPU, PP1V8_SDRAM, PP1V2_SDRAM, PP_VAR_SOC, PP0V95_FIXED_SOC, PP3V0_Tristar, PP3V0_NAND, PP1V8_ALWAYS and PP1V0.
- The PMIC also generates, what I would consider secondary, yet still important voltage rails for the following sub-systems: PP3V0_MESA, PP1V8_VA_L19_L67, PP3V0_PROX_ALS, PP3V0_PROX_IRLED, PP3V0_IMU, PP3V3_USB and PP3V3_ACC
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Quality info right here, Thanks for this
I have a question about the voltage rails- are they always present, even when the device is turned off?
@morticool Most of them are present all the time (once the phone is powered up) but a few are only present when needed, such as PP_GPU, the LCM rails etc.
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What makes you say "motherboard short"? Do you actually have a short to ground on a power line? If so--which one?
Or are you using the term "motherboard short" to mean "phone won't turn on". In this case you have an equal chance of the opposite problem--an open line or bad chip. Since Tristar is required for the phone to boot, and is the last thing you touched--I'd start there.
Differentiate between a short and an open data line with D.C. Power supply
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please how do you differentiate between a shirt and an open data line with DC power supply
2 件のコメント
Hi soldiers i need help I phone 6s when put u2 ic for charging phone works a while but after couple of hours start rebooting and switch of 3 times same happens and solution for me guys will be very appropriate o mail me on asichief@yahoo.com
Asif さんによる
Hello Asif. This is a public forum and the purpose is to help anyone and everyone at the same time. If someone gives you private information...that doesn't really help the community...does it?
So please post a question of your own, with all of the pertinent information including the history of the device and you will get all the help that you need.
The moderators thank you!
Minho さんによる