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smithinator
18-12-2010, 04:11 PM
Hi i need to find some capacitors to replace several dead ones on a motherboard i was given:

I need:

5x 3300uf 6.3v capacitors
3x 680uf 4v

Where can i buy these capacitors online (i cant find them in any stores in my area) and is there anything else i have to look for when buying capacitors for a motherboard? thanks

Myth
18-12-2010, 04:27 PM
Read my thread here regards info for capacitors
http://forums.pcworld.co.nz/showthread.php?t=113844

If you have a Jaycar store anywhere near you, they can get them in for you.

smithinator
18-12-2010, 04:49 PM
Thanks for the link to your thread it was very helpful. i live in a pretty rural place so i have to order them online i checked the dse and jaycar websites but i couldn't find the ones i need, do you know of any other places i can order them from?

Agent_24
18-12-2010, 04:49 PM
Jaycar might be OK if they are Samxon brand.. BUT you have to make sure you get the right series (The GF series aren't good)

Much better to get something like Panasonic FM from RS-Components or Farnell.

Check out www.badcaps.net if you have questions. You do need to get the right capacitors, you can't just put any old thing in there.

SP8's
18-12-2010, 05:28 PM
Got mine online via Farnell ... good service considering they came from Oz as they were out of stock in NZ ... :D

smithinator
18-12-2010, 06:47 PM
is this one good to replace my 3300uf 6.3v capacitors?

http://newzealand.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=4490873

i cant find any 680uf 4v caps where would i find these?

both types of capacitors are marked with 105 degrees C is this something i need to consider when buying the replacements?

do i have to worry about the ripple current when buying replacement caps?

SP8's
18-12-2010, 08:05 PM
I'm only aware that they should be low ESR caps .... but I'll have to leave it up to those more knowledgeable in electronics than I to explain the reasons why. I do know that it does pay to get a reputable brand ... there's some shockers out there apparently.

Agent_24
18-12-2010, 09:00 PM
It depends on what the original series are, and what part of the circuit they were designed to go in. VRMs for example invariably need low ESR capacitors.

As a basic rule, look up the series and brand of your capacitors, noting down ESR and Ripple current specifications.

Then, looking on RS or Farnell, find a series of the same voltage\capacitance which has the same (or LOWER ESR) and the same (or HIGHER Ripple current)

Deviating from the original too much can cause problems, but this varies by motherboard and the circuit itself.

Consider also the size, don't buy something which won't actually fit on your board!


If you are serious about replacing your capacitors I strongly suggest you post about this on Badcaps.net so as to get even more advice from those who do this a lot more than I do.

smithinator
19-12-2010, 01:02 PM
Thanks for all your help ill post it on that website and hopefully ill get this motherboard in working order again :)

Agent_24
19-12-2010, 03:23 PM
If you can solder well then there is little reason for the board not to work again.

Billy T
20-12-2010, 03:48 PM
I'm only aware that they should be low ESR caps .... but I'll have to leave it up to those more knowledgeable in electronics than I to explain the reasons why. I do know that it does pay to get a reputable brand ... there's some shockers out there apparently.

Low ESR means low 'equivalent series resistance' which in layman's terms is a measure of how effective the capacitor is at filtering noise. Ripple current ratings (RCR) quantify how much current the capacitor can safely pass and the lower the ESR, the higher the RCR.

Noise on computer voltage supplies can corrupt data, hence the need for high quality capacitors. Removal (desoldering) and installing the new caps must be done with great care as multi-layer boards are susceptible to damage from overheating and the physical strain of withdrawing the faulty caps. It is not really a job for the soldering novice.

I'd use RS Components or Farnell as a source, and read one of the 'How To' web pages dedicated to this topic.

Cheers

Billy 8-{)