I try post information on what I know from experience, (not suspect).Дuring the startup process the BIOS does checks of the P.O.S.T. LapGuy: This is a blog and not a forum- Forums elicit too many posts that are unrelated, or totally incorrect. I initially thought that the issue could be with the dc jack but i do not see any visible signs of jack being loose or anything, otherwise i guess the system would not even try to power on.I am a novice & cant pinpoint on the exact cause of the problem. I am not sure if that is the culprit which is stopping the computer from powering on. I saw that on the motherboard just under the power jack there is a very small brown colored on the top inductor/resistor is swollen on both sides. I have checked the motherboard for possible issues with blown chips or capacitors. Still the same issue powers on, gives no beep then shuts down. I farntically searched for all possible trouble shooting like hard reset, took all components apart from the motherboard & then reseated all. During the brief 3 secs the lights come up, there is no fan movement, there is no battery or charging led light. Hi friends, My dell latitude d620 suddenly shut down without any error or beep & then when the power button is pressed, the caps lock, num lock, scroll & the power led light up & remain steady only for 3 secs & then shuts down again without any beep or error. Imagine this- Lightning is POS charged clouds arcing to NEG (Earth/Ground) not jumping from ground to the clouds. Negative electrons are 'pulled up' from Grounded circuits (NEG). Voltage is carried over the POS circuit of electronics, and Current is pulled up from the NEG circuit. Question 2: Does the center barrel carry any current. Essentially the coil FL1 is just a jumper, but the nature of coils is to push voltage forward. Sometimes when removed, the previous arcing my had eaten the contacts solder ends, so you would not be completing the circuit. When replacing, you can use an old part from a dead laptop, just make sure it has the soldered ends. So you will need to check the pads, or circuit directly before & after the filter. Many times you may place the meter leads on the filter 2 soldered ends, but the main pads where the Filter sits has the gap. Question 1: Can you test FL1 in circuit? Yes but the filter may not be the exact problem, it is whether the filter is passing voltage. I would like to know if a continuity test is sufficient to tell if the filter is good, and when you say replace do you reuse the original filter or is it a new part? Also, does the pin in the barrel of the dc plug of the power supply carry any current? Several questions were asked directly and I will post/answer here so that everyone will benefit. If you get no lights or anything with adapter plugged in- it is usually a failed negative circuit. If you wiggle the jack with the adapter plugged in and the lights come on briefly it is a failed POS circuit. In picture 2 voltage was checked at pins 1,2,3 to see if voltage reached the MOSFET. The white dots are only Pin 1 indicators or orientation markers. The silver dots on the motherboard in a circuit are test points. If you check the coil only, sometimes you may not have contact to the pad, which is the original problem. Try to test pad contact area and not just the coil. In this case if you cannot find a replacement, you can simply turn the coil upside-down, and make sure you have positive voltage on the circuit. FL1 cannot handel the surge when plugged in and eventually arcs then lose contact with the solder pad. In this instance the laptop was a couple of years old before it failed. Sometimes it may be years before it finally lose contact, other times only months pass. Perhaps eating away at the Filters pad, due to the current it is carrying. From my guess, the solder on the leads of FL1 tend to lose contact after regular use. You can tell by the white and silver cases used. Most of the motherboards use the same general layout and design. This is a common problem with the Dell Inspiron 1501/E1705/6000 series.

Dell inspiron won t turn on