It could be something easy, or it could required desoldering whole sections of a decades-old relic.
|
|
And here's a video of the NAND desoldering process:Why it could work: This method would allow the FBI to try an infinite number of guesses for the passcode.
|
|
For professional laptop, game console and other electronics repair, special repair systems are used. These repair systems usually combine several components: hot air gun, soldering iron, desoldering gun, etc. This equipment allows effective desoldering and soldering large BGAs. These operations require special approach and certain amount of process automation.
|
|
Used solder contains some of the dissolved base metals and is unsuitable for reuse in making new joints. Once the solder's capacity for the base metal has been achieved it will no longer properly bond with the base metal, usually resulting in a brittle cold solder joint with a crystalline appearance. It is good practice to remove solder from a joint prior to resoldering—desoldering braids or vacuum desoldering equipment (solder suckers) can be used. Desoldering wicks contain plenty of flux that will lift the contamination from the copper trace and any device leads that are present.
|
|
Desoldering requires application of heat to the solder joint and removing the molten solder so that the joint may be separated. Desoldering may be required to replace a defective component, to alter an existing circuit, or to salvage components for re-use. Use of too high a temperature or heating for too long may damage components or destroy the bond between a printed circuit trace and the board substrate. Techniques are different for through-hole and surface- mounted components.
|
|
Solders can be removed using a vacuum plunger (on the right) and a soldering iron. In electronics, desoldering is the removal of solder and components from a circuit board for troubleshooting, repair, replacement, and salvage.
|
|
A solder wick on a reel Solder wick, before use ... and soaked with solder and residue Desoldering braid, also known as desoldering wick or solder wick, is finely braided 18 to 42 AWG copper wire coated with rosin flux, usually supplied on a roll. The end of a length of braid is placed over the soldered connections of a component being removed. The connections are heated with a soldering iron until the solder melts and is wicked into the braid by capillary action. The braid is removed while the solder is still molten, its used section cut off and discarded when cool.
|
|
To use an AGP 8x card in a G4, pins 3 and 11 must be somehow disabled; this can be done by placing tape over the conductive part of the pin, slicing the PCB traces, or on some cards, desoldering surface mount resistors.
|
|
They may have different types of tips for different applications. Desoldering iron is usually made in a shape of a gun. It is capable of taking in the air (vacuum pickup) and solder alloy. Non-contact heating tools include hot air and infrared heaters.
|
|
To do this, the cartridge must be unscrewed, opened up, and the old battery would be removed and replaced. This may require desoldering the dead battery and soldering the replacement in place. SNK used round, flat watch batteries for saving information on the cartridges. The cartridge is inserted into the console cartridge slot.
|
|
Such hot plates are usually referred to as corrosion- resistant hot plates. Hot plates are widely used in the electronics industry as a method of soldering and desoldering components onto circuit boards. Hot plates with two heating surfaces are used to fuse plastic pipes. Many of these pipes are over 90-centimeter diameter.
|
|
Each joint must be heated and the solder removed from it while molten using a vacuum pump, manual desoldering pump, or desoldering braid. For through-hole mounted devices on double-sided or multi- layer boards, special care must be taken not to remove the via connecting the layers, as this will ruin the entire board. Hard pulling on a lead which is not entirely free of solder (or with solder not thoroughly molten in the case of a soldering iron tip heating all pins) may pull out a via. To remove and recover all components, both through-hole and surface-mount, from a board which itself is usually no longer needed, a flame or hot air gun can be used to rapidly heat all parts so they can be pulled off.
|
|
Here you can see that moisture in the circuit board turned to steam when it was subjected to intense heat. This produces the so-called "popcorn effect." Desoldering the chips is done carefully and slowly, so that the heat does not destroy the chip or data. Before the chip is desoldered the PCB is baked in an oven to eliminate remaining water.
|
|
A soldering iron or hot air gun can be used with desoldering braid. The precise placement of the new unit onto the prepared pad array requires skillful use of a highly accurate vision- alignment system with high resolution and magnification. The smaller the pitch and size of the components, the more precise working must be. Finally the newly placed SMD is soldered onto the board.
|
|
This prevents the so- called popcorn effect, at which the remaining water would blow the chip package at desoldering. There are mainly three methods to melt the solder: hot air, infrared light, and steam-phasing. The infrared light technology works with a focused infrared light beam onto a specific integrated circuit and is used for small chips. The hot air and steam methods cannot focus as much as the infrared technique.
|
|
Electrically operated pumps are used for several purposes in conjunction with a hand-held head connected by a tube. Suction pumps are used to suck away molten solder, leaving previously joined terminals disconnected. They are primarily used to release through-hole connections from a PCB. The desoldering head must be designed so that the extracted solder does not solidify so as to obstruct it, or enter the pump, and can be removed and discarded easily.
|
|
Desoldering is a very important stage in PCB repair. It is often needed to disassemble some components just to make sure they work or check their condition. That is why it is important to detach the elements without any possible damage to them. The means that may be integrated in soldering stations are: SMD hot tweezers heat up and may not only melt the solder alloy but grab the needed component as well.
|
|
Desoldering is a technique used to extract higher-value materials like gold and silver which can release chemicals and damaging fumes when done improperly. In addition to contributing to air pollution, these toxic e-waste particulates can contaminate water and soil. When it rains, particulates in the air are deposited back into the water and soil. Toxic e-waste air particulates easily spread throughout the environment by contaminating water and soil which can have damaging effects on the ecosystem.
|
|
If they do not need to be re-used, some surface-mount components can be removed by cutting their leads and desoldering the remnants with a soldering iron. If they may not be destroyed, surface-mount components must be removed by heating the entire component to a temperature sufficient to melt the solder used, but not high or prolonged enough to damage the component. For most purposes a temperature not exceeding for a time not exceeding 10 seconds is acceptable. The entire board may be preheated to a temperature that all components can withstand indefinitely.
|
|
A typical spring-loaded solder sucker A solder sucker partially dismantled showing the spring A desoldering pump, colloquially known as a solder sucker, is a manually-operated device which is used to remove solder from a printed circuit board. There are two types: the plunger style and bulb style. (An electrically-operated pump for this purpose would usually be called a vacuum pump.) The plunger type has a cylinder with a spring-loaded piston which is pushed down and locks into place. When triggered by pressing a button, the piston springs up, creating suction that sucks the solder off the soldered connection.
|
|
Heating may be accomplished by passing the assembly through a reflow oven or under an infrared lamp or by soldering individual joints [unconventionally] with a desoldering hot air pencil. Reflow soldering with long industrial convection ovens is the preferred method of soldering surface mount components to a printed circuit board or PCB. Each segment of the oven has a regulated temperature, according to the specific thermal requirements of each assembly. Reflow ovens meant specifically for the soldering of surface mount components may also be used for through-hole components by filling the holes with solder paste and inserting the component leads through the paste.
|
|
Veroboard is similar in concept and usage to a plug-in breadboard, but is cheaper and more permanent--connections are soldered and while some limited reuse may be possible, more than a few cycles of soldering and desoldering are likely to render both the components and the board unusable. In contrast, breadboard connections are held by friction, and the breadboard can be reused many times. However, a breadboard is not very suitable for prototyping that needs to remain in a set configuration for an appreciable period of time nor for physical mock-ups containing a working circuit or for any environment subject to vibration or movement.
|
|
Desoldering a contact from a wire Soldering (AmE: , BrE: ) is a process in which two or more items are joined together by melting and putting a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, soldering does not involve melting the work pieces. In brazing, the work piece metal also does not melt, but the filler metal is one that melts at a higher temperature than in soldering. In the past, nearly all solders contained lead, but environmental and health concerns have increasingly dictated use of lead-free alloys for electronics and plumbing purposes.
|
|
Commonly referred to as a "Chip-Off" technique within the industry, the last and most intrusive method to get a memory image is to desolder the non-volatile memory chip and connect it to a memory chip reader. This method contains the potential danger of total data destruction: it is possible to destroy the chip and its content because of the heat required during desoldering. Before the invention of the BGA technology it was possible to attach probes to the pins of the memory chip and to recover the memory through these probes. The BGA technique bonds the chips directly onto the PCB through molten solder balls, such that it is no longer possible to attach probes.
|
|
Generally the emulation only includes raw hardware logic, such as for the CPU and RAM, and specialized DSPs such as tone generators or video sprites. The MESS emulator does not include any programming code stored in ROM chips from the emulated computer, since this may be copyrighted software. Obtaining the ROM data by oneself directly from the hardware being emulated can be extremely difficult, technical, and expensive, since it may require desoldering of integrated circuit chips from the circuit board of the device they own. The desoldered IC is placed into a chip reader device connected to a USB or serial port of another computer, with pin sockets on the reader specifically designed to match the chip package shape in question, to perform a memory dump of the ROM to a data file.
|
|
Desoldering an IC with a JBC hot air system Quad Flat Package (QFP) chips have thin leads closely packed together protruding from the four sides of the integrated circuit (IC); usually a square IC. Removal of these chips can be problematic as it is impossible to heat all of the leads at once with a standard soldering iron. It is possible to remove them with the use of a razor blade or a high- rpm craft tool, simply by cutting off the leads. The stubs are then easy to melt off and clean with a soldering iron. Obviously this technique entails the destruction of the IC. Another method is to use a heat gun or pencil butane torch and heat up a corner, and gently pry it off, working the torch down the leads.
|
|
Electronic assembly (PCBA) Rework (or re-work) is the term for the refinishing operation or repair of an electronic printed circuit board (PCB) assembly, usually involving desoldering and re-soldering of surface-mounted electronic components (SMD). Mass processing techniques are not applicable to single device repair or replacement, and specialized manual techniques by expert personnel using appropriate equipment are required to replace defective components; area array packages such as ball grid array (BGA) devices particularly require expertise and appropriate tools. A hot air gun or hot air station is used to heat devices and melt solder, and specialised tools are used to pick up and position often tiny components. A rework station is a place to do this work—the tools and supplies for this work, typically on a workbench.
|
|
Desoldering of an SMD capacitor A tube of multicore electronics solder used for manual soldering An improperly soldered 'cold' joint, the wire was not sufficiently heated Broken solder joints on a circuit board, the joint on the right, although unbroken, has separated from the board Currently, mass-production printed circuit boards (PCBs) are mostly wave soldered or reflow soldered, though hand soldering of production electronics is also still widely used. In wave soldering, components are prepped (trimmed or modified) and installed on the PCB. Sometimes, to prevent movement they are temporarily kept in place with small dabs of adhesive or secured with a fixture, then the assembly is passed over flowing solder in a bulk container. This solder flow is forced to produce a standing wave so the whole PCB is not submerged in solder, but rather just touched.
|
|
It is not possible to remove a multi-pin part by melting solder on the pins sequentially, as one joint will solidify as the next is melted; pumps and solder wick are among methods to remove solder from all joints, leaving the part free to be removed. Suction pumps are also used with a suction head appropriate for each part to pick up and remove tiny surface mount devices once solder has melted, and to place parts. Hot air pumps blow air hot enough to melt all the solder around a small surface mounted part, and can be used for soldering parts in place, and for desoldering followed by removal before the solder solidifies by a vacuum pump or with tweezers. Hot air has a tendency to oxidise metals; a non-oxidising gas, usually nitrogen, can be used instead of air, at increased cost of equipment and consumables.
|
|
Another problem arises after much use with the motherboard power connector; flap-like metal parts which contact the outside of the plug lose their tension and fail to make contact so that power does not reach the computer. The "official" solution is to replace the connector on the motherboard, which requires partial dis-assembly of the computer and desoldering a part with several pins; many companies charge a considerable sum for the work involved. Various simple alternatives have been suggested; for example a thin "skin" of solder on the outside of the barrel of the connector on the PSU (with care not to overheat the connector's plastic parts; and this thickened connector should not be used with other, not faulty Dell laptops, as it will stretch the springs and damage or even overheat the plug and socket assembly, causing them to melt or bond permanently). One other problem can happen with the wattage rating of the power supply.
|
|