Editing Detecting short circuits (section)

==Locating a short==
If you have a shorted rail in your device, the next step is to locate the short. Again, look for anything burnt or discolored, solder bridges (if the device has been worked on before), maybe a chip with a little hole in it (things like this take some practice to find). If you find anything like that, remove it and check if the short persists. If a visual inspection does not reveal anything, you can try powering up the device (with caution) and checking [https://youtu.be/3GNkrQgiwJs?t=285 if there are any components on that rail that get significantly hot]. Remove any shorted components found and check if the short persists. Be careful, as not every component that gets warm is necessarily shorted. As a rule of thumb, anything that gets too hot to touch is probably dead. Usually, the shorted component is the one that gets a lot hotter a lot quicker than the rest.

If you can't find any (more) shorted components with the above-mentioned methods (because the rail does not supply enough current to heat up the short), but the short still exists, you might need to [https://youtu.be/0OZZdhLrOKo?t=289 Inject voltage into the motherboard]. The idea behind this is that in the area of the short circuit there is more current flowing, resulting in more heat being generated. Be very careful when injecting voltage, you can easily damage your device when you use too much voltage or current. Do not inject many amps of current into a low power rail that usually only supplies a few milliamps. NEVER inject more voltage into a rail than its specified voltage.

Another method you can use is while having power injected into the shorted line you can scan the board with a thermal imaging camera and locate the hottest component in order to locate your short. Then remove the component to check. A similar method is also by using freeze spray or alcohol and noticing which component heats up soonest.

When you still are not able to locate the short, it means that the short is either very low resistance or non-existent. Retrace your steps, remove any wires and bodges you added, check if the short is still there. Visually inspect the area around the rail. Maybe another rail, that is being created from your "shorted" rail, is shorted and causes your problems? "Dead" shorts (very low impedance shorts) are usually caused either by solder bridges or by power components (MOSFETs, diodes, large capacitors). MOSFETs and diodes are usually heatsinked very well, therefore it is harder to see when they dissipate power from a short. Components like the CPU or GPU always measure like a short circuit, so shorts on power rails for them (e.g. CPU_VCORE) are very hard to detect (as a reference, a CPU that uses 25{{nbsp}}W at 0.8{{nbsp}}V core voltage has a "resistance" of just 25.6{{nbsp}}m{{ohm}} and takes over 30{{nbsp}}A, you can easily imagine how much current it would take to heat anything up in a rail like that).