Let’s say your laptop does not start at all. You plug in the power adapter and press on the power button, but the computer will not react. It’s dead and the power or battery charge LED will not light up. What could be wrong? Is it bad power jack or the motherboard is dead? By the way, the power jack (DC-IN jack) is the power socket on the side or back of your computer where you plug the AC/DC power adapter. I’ll explain how to perform basic troubleshooting and find out what is wrong. This is only for experienced people, who know how to disassemble laptops. First of all, test the AC/DC power adapter with a multimeter. It’s very likely that there is noting wrong with the laptop and your problem is related to the power adapter. If the adapter tests fine and output correct voltage, disassemble the computer and remove the top cover. As you see on the first picture, in my example the power adapter plugs into the DC-IN power jack which is connected to the motherboard via a harness.

In some models the DC-IN power jack is soldered directly to the motherboard. Plug in the power adapter and measure voltage at the point where the DC-IN jack or DC harness (like in my case) connected to the motherboard. If you are reading the same voltage as on the AC adapter, it means the power jack or harness works properly and the problem is related to the motherboard. If there is no voltage, most likely there is a problem with the jack or hardness and it has to be replaced. By the way, in some case the problem could be related to the fuse which is usually located somewhere very close to the power jack/harness connector. You can test the fuse with a multimeter. If the fuse is bad, the motherboard will appear to be dead even if there is nothing wrong with the power jack and AC/DC adapter. If that’s the case, replacing the bad fuse should fix the problem. You can support my work! Plug Fuses & Box Cover Units These fuses thread into fuse receptacles.

Two types of threaded fuses are available: Edison Base (brass threads) and Rejection Base (porcelain threads). The two are not interchangeable. Two categories of plug fuses are available. ac indoor unit cleaningThe medium-duty fuses (TL or SL) have a time-delay feature for use on motor circuits. portable ac unit outdoorThe heavy-duty fuses (T or S) are industrial strength products featuring the exclusive Cooper Bussmann dual-element construction. how to reset central ac unitThis spring loaded design provides superior short-circuit and overload protection. The T or S fuses have more time-delay than the medium-duty fuses in order to better protect motors and critical residential circuits. Plug fuses are rated for a maximum of 125Vac. TL and SL four pack (PK4) versions priced per box.

Plug fuses are often used in residential and industrial branch circuit and motor protection. Fuses are used to protect furnace blower motors, pumps, power tools, garage door openers, etc. Motor protection fuses are usually used in conjunction with branch circuit protection. The fuse is often located in a box cover unit. Plug fuses provide a compact and inexpensive method to prevent damage to electrical motors. They help reduce downtime and lower maintenance costs by opening the circuit when a dangerous overload is present. When used for residential branch circuit protection, fuses are typically located in the main fuse panel.During the course of ownership, there's a chance one of the fuses in your car, truck or SUV will blow out. When that happens, the results don't usually create a crisis, but it means that something on the vehicle is no longer working.Most likely, the thing that'll quit working on your vehicle will be relatively minor. For example, it could be the backup lights, the turn signals, the

high-speed setting in the climate control system's fan, the radio, or even the interior lights. case, if a fuse blows, the device in question won't work.For exterior or interior lighting, the possibility of a fuse being the cause of malfunction is quite likely. In fact, for any single item or system in the vehicle, the chances of a fuse being the cause of an electrical failure is high enough that, in most cases, it should be the first thing you check."But I don't know how to check fuses," you mightAfter reading our little primer on fuse inspection and replacement, you'll know how. and you'll get a real sense of satisfaction knowing you were able to troubleshoot a little nit like this without having to go through the hassle and expense of going to the dealership. most vehicles on the road have two types of fuses. Older cars have glass, cylinder-shaped fuses with stainless steel on the ends and glass in the middle. Most newer cars have a different style of fuse that

uses a plastic housing with the fusible link encased in the housing. show the latter type of plastic fuse, a typical fuse box they're housed in and how to determine if the fuse in question is blown. For reference purposes, these photos show fuses and the fuse box from our long-termIn the Focus, the box is located behind a cover, underneath the dash, below and to the left ofAs part of a little five-minute research mission we also determined that our BMW 328i, Volkswagen Passat and Ford Focus long-term cars all use the identical type of plastic fuses shownWe also checked our '99 GMC Sierra pickup and it uses very similar plastic fuses, which areIf a device or system on your vehicle isn't working and you suspect a fuse might be the culprit, the first step is to look in your owner's manual. The manual will help you locate the fuse box and tell you how to access it. On older cars, the box was usually located underneath the dash to the left of the brake pedal or near the parking brake pedal.

There was no cover for it, but it was still a major hassle to view because of the bizarre angle you had to place your head at to actually eyeball the box. new cars, such as the Focus, have a cover that that can be removed with your hand. Or, in the case of our Passat, with a small flat-blade screwdriver. The 328i has a trick setup where the fuse box is hinged and drops down into the open glove box. The Passat, the BMW and the Sierra even come with little pairs of tweezers to facilitate fuse removal. Such is not the case with our Focus.Once you've located the fuse box, you have to determine which fuse needs to be removed for inspection. manual will help you do that. Say, for example, the backup lights don't work. Our Focus owner's manual provides a numerical chart to explain which fuses correspond with which device or system. In the case of the Focus, the backup lights are fuse 39, which is the one we show being removed in the photos. noted, some cars provide a pair of tweezers to help you remove a fuse.

If your car doesn't have this nifty little feature, you're not out of luck. We were able to remove fuse 39 in our Focus with our hand. most cases, you'll need a small pair of needle-nose or standard pliers to get the fuse out of the box. the fuse is singled out and removed, you need to determine if it's blown. This is usually quite easy. the older glass fuses as well as the new plastic ones like shown here, if the metal link inside the fuse is separated, the fuse is toast. If not, then it's still good and can be reinstalled. (straight from our Focus owner's manual) shows the difference between a good fuse and blown one. the fuse is blown, the next step is finding a proper replacement. Some cars come with a supply of spares; otherwise you'll need to make a quick trip to the auto parts store. The most critical element to replacing a fuse is using the exact same amperage rating as the blown one. If you use a fuse with different amperage rating, you risk either blowing the fuse again, or damaging the equipment the fuse is designed to protect.

idea behind a fuse is that it's supposed to blow if there's a surge or short in the device orFor example, if it's a 10-amp fuse that needs replacing and you replace it with only a 5-amp fuse, the smaller fuse will blow much sooner than it needs to. Conversely, if you replace that 10-amp fuse with a 20-amp unit, it's possible you'll damage the part or system before the fuse has a chance to break and save the component.So, once you determine the fuse is blown and procure a suitable replacement, it's time to reinstall the new one. This is the easiest part. plastic fuses, they plug right back into the fuse box and usually fit into place with a little pressure fromWith older glass fuses, the installation process is a bit tougher, as they are installed by pressing one end at a time. We'll also note that with the glass fuses, different amperage ratings sometimes come in different lengths, so the right amperage rating is not only crucial from an electrical standpoint, but from a sizing one, too.