Repairing

Sending in a device for RMA is time consuming, invasive, and sometimes costly. Sometimes, the only way to do it your way is to do it yourself. And along the way, you can put your own personal spin and customisations in your device at the same time!

I've been repairing electronic devices since around 2015. I didn't have a shop per-se, but I would spend summer breaks buying broken game consoles from eBay for repair, then keeping them for super cheap or reselling them for profit. My main console family was Nintendo 3DS, and is now the Nintendo Switch.

In 2022, I became employed with uBreakiFix by Asurion, an American-wide franchise of stores offering official in-warranty repair solutions for Google and Samsung phones.

This page will list some tips and techniques for repair that I find useful. A dictionary of terms I use are at the bottom of the page.

Dictionary

Dictionary of Terms

AC	Alternating current, used in contrast to direct current (battery power).
Bridge	A bridge is a connection between two components, usually via solder.
Cap	Short for capacitor.
Digitiser	A digitiser (digitizer) is any device that converts analog input into digital input. In practice, this is usually just a touchscreen. Note that this is different from the display, which displays images.
Flux	Magic bonding liquid. That's all you need to know. Applying this to a trace will help the solder stick only to the intended target, and not solder mask or other unintended components. It can also assist in heating up the entirety of a joint as flux is a very good heat conductor. This means that touching recently heated flux can harm your skin. Flux should be cleaned after use as it often leaves a residue which can become conductive after use.
FPCB	Flexible circuit board connector. This is the proper name for the "lego-style" connectors at the end of FPCs.
FPC	Flexible printed circuit. This is the proper name for "ribbon cables" used in small devices. Ribbon cables are thicker and use shielding around each wire, whereas FPCs are generally traces laid on a flexible circuit board.
Known good	In troubleshooting, this refers to using a control variable -- a component which is known to be fully functional, used alongside a device that is exhibiting issues. Something that is known to be good for use. This determines if a given issue is caused by the faulty external component, or the device itself.
IC	Also known as a microchip, an IC is simply a wafer of silicon intended to perform a specific task, such as power management. It stands for "integrated circuit".
IPA	Isopropyl alcohol/isoproponal. A quick-drying non-conductive liquid commonly used to cleanse and disinfect.
Joint	This is a bridging of a surface and component with cooled, solid solder to an component.
JIS	Japanese Industrial Standard. In the context of repair, this usually means a "+ shaped" screw bit similar in shape to Philips.
"PCB"	This can also be referred to as a motherboard, mainboard, main PBA, or printed circuit board. This is the primary board that consists of fiberglass that the primary components of the device, such as the CPU, GPU, RAM, antennas, etc, all connect to. Some PCBs are comprised of many layers, where circuits may be hidden.
Reseat	Reseating is a process of removing and reconnecting a component. This process may clear out dirt and debris causing a failed connection while also ensuring that all pins and contacts are aligned.
"Solder mask"	A PCB houses traces, which are intended electrical paths to complete a circuit. These traces are usually copper, gold, or sometimes dark green. The rest of the board will be covered in a green layer, which gives motherboards their stereotypical color. That is solder mask, and it helps electricity to complete its intended path without interfering with other circuits.
Solder	This is a type of metal alloy that melts at a relatively low temperature. We can use solder to electrically conjoin two components together.
Shield	This usually refers to any sort of protection for an electronic component. Examples range from metal cowlings covering an network IC, to the plastic tubes covering a cable.
SMD	Surface-mounted devices. This refers to any component mounted directly atop a PCB, making a direct connection to the traces on the board.
Ground	Necessary to complete a circuit, or else excess voltage would travel into the component which may force it to suffer an overvoltage or arc.
Ribbon cable	Commonly used interchangably with FPC, though ribbon cables are an alignment of individual cables in a
Trace	An trace on a circuit board is another name for an electrical path. They will also be referred to as lines, lanes, and paths. Circuit boards may have multiple layers of traces on a single wafer, so repairing damaged traces isn't always possible.
"Microcontroller unit (MCU)"	A multi-purpose unit that monitors and controls numerous components of a circuit, usually including power management and clock.
"RTC"	Real-time clock. This is not to be confused with the device clock, which is also known as cycle speed. A real-time clock keeps track of the time as a stored integer, usually a raw value from an epoch (usually the Unix epoch). The OS derives time by converting the raw value into a human-readable time format and then applying an offset for the user's applicable time zone.
"ZIF"	Zero-insertion force connectors. Most FPCs connect to these. These are often in the form of flap or latch ZIFs, where a latch must be lifted in order for the FPC to become free.

Troubleshooting

Before delving into a repair, it is necessary to determine the primary defects of the device. It is very helpful to understand the how the device works internally beforehand, and how each component interacts with each other in order to make the best judgement on whether a job is suitable to fix. Many software issues may have many physical catalysts, and so can hardware errors. In many cases, a device that appears cosmetically functional yet presents with many assorted issues is very likely to suffer liquid damage or static shorting in some form. This is because a short circuit can either damage many individual components, or a specific component that controls many others, like a microcontroller.

Physical

Physical repairs comprise of primarily cosmetic damage, and can be corrected by replacing a number of components.

ZIF Components

ZIF latches, also known as zero-insertion-force connections, come in a variety of sizes, shapes, and mechanisms. Within most phones, tablets, laptops, and handheld gaming consoles, there are three primary types, and they generally have standardised names. For example, the P6 connector is a four-pin latch-style ZIF that is used for DS and 3DS touch screen receptables.

Electrical

Electrical repairs usually involve some form of direct damage to a PCB and may require soldering, trace repair, and/or use of a multimeter.

Soldering

Soldering involves joining two electronic components using a metal with a low-melt-point called solder.

Desoldering

Most desoldering is achieved using a hot air rework station. The method depends on the type of component, and if it's surrounded or contains any plastic pieces, like most ZIFs.

Standards and symbols

From a manufacturer, a red wires typically contain live voltage, while black wires serve as grounds. This, alongside most standard practices, isn't reliable for devices that have already undergone amateur repair.

Liquid

Liquid damage is inherently unpredictable and should be avoided for all purposes aside from data recovery.

While many liquids, including pure water, are not conductive on their own, the impurities that the liquid will inevitably transport from component to component are. A thorough wash in isopropyl alcohol might remove many of these contaminants, but there may still be shorted components which aren't immediately causing errors, and can cause issues at an indeterminate point in the future. A device that has suffered liquid damage may appear to work, but cannot be guaranteed to be reliable and should not be resold as a refurbished device on principle. Metallic components may now be vulnerable to corrosion.

A very good tool to clean a PCB with is an ultrasonic cleaner, assuming the board doesn't have loose surface-mount components. A screen with liquid damage is a lost cause due to the extremely thin layering.