Need help identifying a capacitor  - Page 1
Forum section: electronics / beginners

author: deathboy
author_rank: Newbie
timestamp: August 15, 2020, 09:01:08 pm
content: My laptop shutdown and now wont turn on..... i opened my laptop and the motherboard show a blown capacitor.. I dont understand the values at the top of the capacitor and what type of capacitor is.. also I would like to know if its possible to change the capacitor and make the motherboard work again just by looking the photos.. and if its possible .. where can i get one of those capacitors..thanks in advance.

author: TimFox
author_rank: Super Contributor
timestamp: August 15, 2020, 09:14:45 pm
content: Looks like 100 microfarads, 25 V, surface-mount aluminum electrolytic. Should be available from all of the standard vendors (Mouser, DigiKey, etc). Note dimensions when using their search engines. I hope you noted the orientation (polarity) before removing the dead part.

author: deathboy
author_rank: Newbie
timestamp: August 15, 2020, 09:22:31 pm
content: searching on internet i found a circuit diagram from the motherboard model... 100U_25V_NC_6.3x6 .... i been looking on internet but cant find 6.3x6 zixe... is there a problem getting one with higher height like 6.3x7.7 or 6.3x8? ... sorry for the questions I'm a newbie..

author: Manul
author_rank: Super Contributor
timestamp: August 15, 2020, 09:31:33 pm
content: If it fits, then height does not matter. But better buy the same height just to be sure.Looks to me as aliuminum polymer type (does not have vents on top).

author: TimFox
author_rank: Super Contributor
timestamp: August 15, 2020, 09:32:47 pm
content: So long as you have an extra mm of vertical space, there should be no problem.

author: janoc
author_rank: Super Contributor
timestamp: August 15, 2020, 09:42:13 pm
content: Well, given those skid marks and that the laptop doesn't turn on, I would hazard a bet that that thing has more wrong with it than just a capacitor. A cap won't blow up by itself like that.Dead power supply that took half of the motherboard with it, by chance?

author: Manul
author_rank: Super Contributor
timestamp: August 15, 2020, 09:50:53 pm
content: As it is power adapter input circuit, check that there is no blown fuse and that there is continuity from 19V socket before reassembling your laptop.By the way, looks kinda strange, is this black burn mark on another side of board under that capacitor? Seems to me more like exploded ceramic capacitor (it is not uncommon for them to get shorted), PCB short or a short to some metal shielding. Never saw an aluminum capacitor to fail like that.

author: deathboy
author_rank: Newbie
timestamp: August 15, 2020, 10:56:59 pm
content: I tought the capacitor could be the problem cause the burn was under the capacitor. I search for images from my motherboard model on internet.. and manage to get those images from the same place... in one of the photos i mark the components that blown.. i dont know what is it..First 3 images are from a motherboard like mine.. just different angles... and the last one is from my motherboard..

author: Manul
author_rank: Super Contributor
timestamp: August 15, 2020, 11:58:52 pm
content: That is almost for sure a small ceramic capacitor blown and there is nothing wrong with a big one.There are two small ceremic capacitors visible. 0805 or 0603 size. Probably only one of them is really blown, another just got black, so look closely. Your laptop should work without one or even both of them, BUT the shorting probably blown a fuse, so check it. Remove any leftovers of a blown capacitor, clean PCB from carbon and check that tracks are not shorted on a blown area. And in general check if that 19V power rail is not shorted somewhere. Replace a fuse if blown and try.

author: perieanuo
author_rank: Frequent Contributor
timestamp: August 17, 2020, 04:17:07 pm
content: hi,look for that power line if it's 'shorted'if it isn't, just put a new C or test without him.if it is, look in schematic which voltage is there.I think it's the 19V so put your charger in without battery connected and see if you got 19vif you don't find the 19V, search for other shorted capacity, died mosfets or died supervisory ICwhen I find some dead voltage line, I eliminate the short.well, sometimes you need power supply with more than 10 amps capability to manually inject the correct voltage, the shorted capacity blows in seconds.other methods involve lot of time, milli ohmeter etcregards,pierre