iPhone Logic Board Repair (2016)
In chapter 2 I have pointed out how a logic boards works and how its main components operate .In this chapter I will discuss the tools needed for fault finding and repair.
3.1. Main tools
As I said before: the smallest repairable logic board components can hardly be seen with the naked eye. So a good microscope is essential. Personally i use a microscope with 10X magnification for most repairs, and 20X magnification for things like trace repair link.
If you have a good budget i would advise a better one: link With this one you have a proper tool for all kinds of logic board repairs. For myself: I love to find items that are the best value for the money .
All components are attached on the board with solder. So to replace a small component a soldering iron is needed. This one works fine for me: link. Many repair shops use a Hakko soldering station like the FM-202. A nice extra about some Hakko stations is that on some of them you can use soldering tweezers. It makes it easier to replace both sides of small components in one try.
Hot air station
To replace an IC a normal soldering won’t do the trick. IC’s are attached onto board with soldering balls. That’s why you can only replace them with a hot air station. I use the following hot air station: link. Many repair shops use a Hakko hot air station like this one: link. In chapter 5 i will explain some basics of how to replace an IC using a hot air.
DC Power Supply
To see if a board powers on properly (boots), and to see if there is a short to GND somewhere, a DC Powers Supply (DCPS) is a valuable tool. This is mine: link
A DC power supply acts the same as a a battery. It provides current. It has a display that shows volts and amps and comes with two probes. A red probe for the positive (+) side. And a black probe for the negative (-) side.
These probes need to be connected to a capacitor on a shorted line to detect heat and to find the damaged component. It can also act as a battery. There are special cables for that. In that case you can see how the board boots and if there is a short on important circuit lines.
When a board consumes energy without having it powered it means a big short somewhere. When a powered on iPhone consumes Amps in standby mode that means there is a smaller short somewhere. These smaller shorts are not easy find in my experience.
To measure faulty components, continuity in lines, and shorts a multimeter is an absolute necessity. In chapter 5 i will explain how to measure these things with a multimeter.
3.2. Knowledge sources
Schematics provide a blueprint of how the boards is build. It shows it’s components and value’s, the way components and lines are connected and their functions. The official iPhone schematics are not publicly made available by Apple, and the ones one the internet are leaked . Personally i avoid them and use a Chinese tool with operates just like the schematics instead. The ZXW tool. The tool comes with some great extras: as well. The tool shows how each component on a circuit line is connected, and it also shows the value of components, and the positioning of IC’s.
Another great source of information are the step-by-step solutions provided by https://itesla.solutions/ The site provides, among other things, step-by-step solutions for most defects. The site charges a subscription fee which I find absolutely worth the money. In chapter 5 i will explain how to use these solutions.
3.3. Further necessary tools
Next I will give a list of some other tools needed for iPhone logic board repair. For these i normally choose the best quality items. I have listed them in the working routine order. The rest of the needed items are common household items like scissors, a toothbrush, needles etc.
For removing and replacing the logic board from a iPhone:
• iPhone screwdrivers
• Scalpel (for removing standoff screws + other purposes)
• Magnetic mat
For testing logic board before and after repair:
• Working housing + lcd
For working on the logic board in general:
• HAKKO Precision Tweezers
• Silicon mat (to work on)
• PCB Circuit Board Holder (especially for shield removal)
For testing parts:
• Freeze spray
• Ultra fine probes for the multimeter
• DCPS cables specially for IPhone
For repairing the board:
• Donor boards
• CyberDoc Liquid Flux
• Kapton Tape
• Desolder Braid Wick
• Reballing stencils
• CyberDoc Desoldering Alloy
• Solder bal’ls
• Cyberdoc insulated jumper wire
• Copper soldering iron tip
• Solder Iron Tip Cleaning Tool
For cleaning board during and after repair:
• 50x Double Tip Foam Swabs
For sourcing parts: