What the heck is it - Page 1
Forum section: electronics / beginners

author: wcs-ic
author_rank: Contributor
timestamp: March 14, 2013, 02:21:50 am
content: I goggled this and come up with nothing, oh and by the way I'm new here sorta been a lerker for a while and finally decided to go legit.

author: ignator
author_rank: Regular Contributor
timestamp: March 14, 2013, 02:32:22 am
content: I'm guessing a 2.5 farad capacitor, for ram holdup. Maybe a few minutes if it's dynamic ram.What is this used in?

author: c4757p
author_rank: Super Contributor
timestamp: March 14, 2013, 02:34:21 am
content: 390µF/2.5V capacitor. From the color of the markings, maybe one of the newer solid electrolyte types, though I can't find anything on the specific series. (My first guess was Panasonic FP series - of course, from the "FP" - but the markings are nothing like what the datasheet shows)Quote from: ignator on March 14, 2013, 02:32:22 amPretty sure that is not a 2.5F cap. 391/2.5 almost always means 390µF/2.5V.I wish manufacturers would put their name or logo on SMD caps like they do with the leaded ones...

author: wcs-ic
author_rank: Contributor
timestamp: March 14, 2013, 02:50:50 am
content: It is on a Toshiba laptop that wont turn on, I tested it with my esr meter and it comes back leaky but I wasnt sure what it was.

author: pspgeek
author_rank: Contributor
timestamp: March 14, 2013, 02:58:19 am
content: I'm almost sure is a cap but the markings could mean many things so not sure about the values.

author: c4757p
author_rank: Super Contributor
timestamp: March 14, 2013, 03:06:09 am
content: Quote from: wcs-ic on March 14, 2013, 02:50:50 amLeaky? Does your ESR meter actually test leakage? Keep in mind that it is a fairly high capacitance, so it will appear leaky if it hasn't had time to charge up.Or do you just mean it had high ESR?

author: wcs-ic
author_rank: Contributor
timestamp: March 14, 2013, 03:57:27 am
content: tested with a Atlas ESR70

author: wcs-ic
author_rank: Contributor
timestamp: March 14, 2013, 05:04:55 am
content: Quote from: wcs-ic on March 14, 2013, 03:57:27 amThis is what it said

author: David_AVD
author_rank: Super Contributor
timestamp: March 14, 2013, 05:09:44 am
content: Err.... was it actually in-circuit?

author: wcs-ic
author_rank: Contributor
timestamp: March 14, 2013, 05:29:06 am
content: Quote from: David_AVD on March 14, 2013, 05:09:44 amMeasures the same both in and out

author: David_AVD
author_rank: Super Contributor
timestamp: March 14, 2013, 06:05:37 am
content: Maybe check the capacitor with a multimeter (on Ohms) and see what it reads.

author: wcs-ic
author_rank: Contributor
timestamp: March 14, 2013, 08:14:17 am
content: Quote from: David_AVD on March 14, 2013, 06:05:37 am.715

author: Rerouter
author_rank: Super Contributor
timestamp: March 14, 2013, 08:17:59 am
content: if thats ohms, then very likely its faile dshorted, but leave it a while to charge up and stabalise,

author: mariush
author_rank: Super Contributor
timestamp: March 14, 2013, 08:19:25 am
content: The color and the FP marking would make you think it's a Nichicon / FujitsuFunctionalPolymer capacitor, 390uF 2.5v ... example of datasheet:ftp://helpedia.com/pub/temp/datasheets/capacitors/Nichicon/Polymer/2009fpcap_catalog_s8.pdfThe ESR of these capacitors is super low, 0.01 ohm or less.The problem I have is that those capacitors have FP on them only if they're through hole, if they're surface mounted they actually have the series code on them ... cs, ck, cg etcIt's not unheard of to have some custom batch of capacitors made, especially if it's a Toshiba, but it could also very well be some polymer / functional polymer made by another company. Though who use that intense red color... i don't know.But basically, the ESR70 and these cheap esr meters are not accurate enough to determine the ESR of polymer capacitors, these have esr under 10mOhm and the esr meter has 0.01 ohm as the lowest value it reports.

author: wcs-ic
author_rank: Contributor
timestamp: March 14, 2013, 12:32:29 pm
content: So whats the consensus replace it and if so with what? Man this is why I hate working on Toshiba stuff.

author: wcs-ic
author_rank: Contributor
timestamp: March 14, 2013, 01:04:00 pm
content: Quote from: Rerouter on March 14, 2013, 08:17:59 amyep ohms, There are 2 of these one on the board and one off they test the same.

author: Neganur
author_rank: Unknown
timestamp: March 14, 2013, 05:57:22 pm
content: I'm pretty sure this is a low ESR polymer electrolytic cap (Nichicon?)http://www.nichicon.co.jp/english/products/pdf/2012fpcap_catalog_all.pdfProbably no point measuring them in circuit unless you know what the circuit they're in is like. Grab a second soldering iron and pull one off to be sure (use extra solder), they're quite reliable and don't usually die. (or so those motherboard manufacturers claim)

author: David_AVD
author_rank: Super Contributor
timestamp: March 14, 2013, 11:00:01 pm
content: You are measuring the capacitor correctly (between the pads) aren't you?The reason I ask is that I find it hard to believe you have two capacitors that are such a dead short.

author: wcs-ic
author_rank: Contributor
timestamp: March 15, 2013, 02:38:32 am
content: yep , I even removed one flipped it over stuck it is some putty to hold it still and measured it with some needle tips same result. Kinda weird.

author: mAJORD
author_rank: Contributor
timestamp: March 15, 2013, 04:33:20 am
content: Quote from: David_AVD on March 14, 2013, 11:00:01 pmNot odd if theyre both sitting on a supply rail with a blown ( in_out short) reg. Probably other stuff dead too if that happened

author: wcs-ic
author_rank: Contributor
timestamp: March 15, 2013, 05:37:25 am
content: Quote from: mAJORD on March 15, 2013, 04:33:20 amKinda what I thought, it's a friends laptop so I was just doing him a favor. All the other caps test good but these 2 are kinda odd and appear more work to find replacements than it's worth not knowing the condition of the other components. If nothing else it got me to join the forums, thanks to all who have put in there 2 cents.

author: amyk
author_rank: Super Contributor
timestamp: March 15, 2013, 11:24:10 am
content: What's the model number of the laptop? It might be possible to find a schematic for troubleshooting.(I assume the OEM model is not a Quanta MX3, which also has a 390u/2.5V cap at position PC78...)

author: wcs-ic
author_rank: Contributor
timestamp: March 15, 2013, 07:51:43 pm
content: It is a Satellite L745-S4210 and the 2 caps in question appear to be 390u/2.5V at positions PC60 and PC78

author: David_AVD
author_rank: Super Contributor
timestamp: March 15, 2013, 10:04:00 pm
content: If the caps are shorted, replace them and move on to the next step.

author: wcs-ic
author_rank: Contributor
timestamp: March 15, 2013, 10:39:50 pm
content: I wasn't sure of there values at first or a good suppler, I have not bought and of this type, Believe it or not I usually use Amazon