Released September 25, 2015. Model A1688/A1633. Repair of this device is similar to previous generations, requiring screwdrivers and prying tools. Available as GSM or CDMA / 16, 64, or 128 GB / Silver, Gold, Space Gray, or Rose Gold options.

917 Questions View all

iPhone 6S Tristar IC Replacement Tips

Hi everyone,

My girlfriend iPhone 6S is not charging, and for what I have searched the problem is related with the Tristar IC (U4500).

I already bought the U4500 component and I have all the material necessary form the replacement.

For what I have searched about the problem that I mentioned, the only thing that I need to do is to replace this Tristar IC (U4500) (but if I’m wrong, I appreciate if anyone cloud clarify me, on other possible reasons for this problem).

With that said I have a few questions that I would like to know the answers before try anything with the iPhone.

  1. What temperature should the soldier station be, to remove to Tristar IC, without cause unwanted damage to other components?
  2. How much flux should I apply to avoid damaging other components?
  3. In the removing process how long (seconds or minutes), should I inflict heat to remove the IC chip (an approximated time)?
  4. When heating, my movements should be circular around the spot, or as steady as possible focusing on IC?

Thanks in advance for the help.

Answered! View the answer I have this problem too

Is this a good question?

Score 0
Add a comment
Deck the Halls
With tools and Fix Kits

1 Answer

Chosen Solution

First, Be certain you are willing to risk the loss of the phone if you are not successful and make any mistakes. I would recommend finding a "Donor" board and experimenting with it first, as there are several heat stations on the market and they are all a bit different with their heat settings and airflow.

(Personally...I try to get in and out quick, minimizing the time I am applying heat to the board. I set my airflow at 40% and heat no more than 380C but usually stick around 360C for this chip).

I apply Kapton tape around everything surrounding the IC and a couple coins to act as heat sync on either side, also move antenna cables out of the way. After putting a small amount of flux around the chip, apply heat using the smallest attachment directly on the center of the IC as it is so small (Not like the Baseband or NAND where you have to move around the chip in a circular motion).

Keep an eye on the solder on Capacitors, etc to see the solder begin to flow, gently nudge the ic as you are heating it until it begins to flow (Do not pull it up until you are certain that it is liquid or you will pull pads and end up having to run pain in the butt traces to repair the pads)...and keep heat pointed away from NAND and U_PMU_RF as you are heating.

Then, use "Low Melt" on the tip of your soldering iron on the pads after removing it to make it easier to clean the pads. Don't try wicking with an Iron...after using lowmelt, you can use a small piece of wick and tweezers to use it like a paint brush to gently brush the pads with your Air set at about 220C to 240C making sure you keep them moist with clean Flux.

When you reseat the new IC, (On cleaned pads and very smooth surface), add a small amount of flux first, place the IC keeping track of orientation and hold it still in place for a few so it doesn't cause bridges by sliding around. Once it gets set in place, you can let go and keep heating and it will find its way to its pads on its own if you cleaned well enough.

Watch several videos on Youtube first to get a good idea of what others are doing (Here is one from Chris Long) and again, if possible, practice a bit...even if you don't have a Iphone Logic Board, find an old piece of electronics you can scrap and play around with it.

Best of Luck!

Block Image

Was this answer helpful?

Score 3

Comments:

Thanks for the reply, I will carefully study your tips and try to put them in practice.

I just want to make two more questions, I have, because of some feedback I had when talking with some friends.

1. They told me to be sure about the brand of the flux I’m using and try to use one with a reasonable quality. The one that I’m using is from Amazon, with the name “Mercury 703.003 30 gram Solder Flux Tin” (I tried to put the link here, but the iFixit website didn´t let me, and I could not find why, sorry. But if you search on Amazon by that name you find it), in your opinion do you think the quality is good for the purpose, or do you recommend another brand?

2. About the time that I should heat the Tristar IC, I had the feedback that some people had to heat form more than a minute, and I listen people that with not more than 30 seconds, removed the Tristar IC. Is this related with the amount of flux used on the place, or that exist any other reason related to this?

Once again, thanks for the help.

by

Personally, I have never used the Flux you mention. I looked it up but not sure what to say about it. I use and many in the industry use: https://www.amazon.com/ChipQuik-SMD-291-...

It normally takes 30 seconds to a minute to remove it...it just depends on when the solder melts and that depends on the heat and airflow you use. That's why I encourage you to practice a bit on a donor board. Too little heat and it could take too long, and too much heat can cause issues on surrounding components and the Baseband IC on the back side of the board under it.

I like to use a bit more heat but get in and out quick to get it off, and then lower heat to clean the pads and it usually sets back in place in under 30 sec with 350C range.

Don't be shy with the flux, don't drown it but a little more is better than not enough...just remember to clean it all off after it cools down. The more you put on the more you clean :)

by

Add a comment

Add your answer

Rey Volt will be eternally grateful.
View Statistics:

Past 24 Hours: 3

Past 7 Days: 14

Past 30 Days: 50

All Time: 116