my capacitors are different sizes (help)

[terry5880]

hi all i have a lcd monitor for pc and the power has gone completley so i opened it and see that all 6 of caps on the power board are not flat at the top they are 470uf 105 c 25v but i bought some more only difference is the ones i bought are little smaller does this matter . thanks in advance

[brethin]

Re: my capacitors are different sizes (help)

Yes it could matter. You only provided 470uf 105c 25v for information. You need to also provide (know) what the ESR and Ripple are of the ones you are replacing, knowing the Brand and Series will help find this out. The new caps can be smaller as long as the ESR is the same or lower and the Ripple is the same or higher, and the other 3 specs are the same. In other words not all 470uf 105c 25v caps are the same, even if they are the same size unless they are the same Brand and Series.

[terry5880]

Re: my capacitors are different sizes (help)

ahhh thanks how do i find this out please

[mariushm]

Re: my capacitors are different sizes (help)

Tell us what's written on the capacitors and/or make pictures of them.

Tell what's inside the monitor AND on the capacitors you bought. If we know what you already have in the monitor, we would be able to tell you if what you bought is good enough, or tell you what to buy otherwise.

[terry5880]

Re: my capacitors are different sizes (help)

on the power board inside the monitor thereare 6 capacitors in them it says TM 105CM XUNDA
470uf25V AND THE ones i bought say SD263 105 C A 470uf 25v

[terry5880]

Re: my capacitors are different sizes (help)

the ones i bought are tiny bit smaller than ones on board ones i bought are 8mm by 16mm radial

[terry5880]

Re: my capacitors are different sizes (help)

as you can prob tell im not to clued up on capacitors so any other info u need to be able to help please let me know i will try my best to get it

[mariushm]

Re: my capacitors are different sizes (help)

Unfortunately, SD263 doesn't tell me anything... it might be a code for a series of chinese capacitors made by various companies there. So the technical specifications might vary from manufacturer to manufacturer.

Further, you say the new ones are 8mm in diameter... 8mm is usually used for capacitors rated for lower voltage or for less capacity. So this makes me concerned about how much voltage those capacitors would actually be able to stand or how reliable they'd be in time.

With all this in mind, I'd suggest not to use the capacitors you bought.

Xunda is also not so popular Chinese manufacturer, but at least they have a website here: http://www.chinese-xunda.com/cn/product.asp

You can find there the TM series datasheet, which tells you it's a "low impedance" , "high ripple" series of capacitors.

Further down in the datasheet you find the 470uF 25v in two sizes:

8x14 905mA ripple, 0.069 ohm impedance
10x13 1120mA ripple 0.060 ohm impedance

As you say the new ones are smaller, this means you probably have the second option installed, the 10x13 capacitor.

So now you can go in various stores and pick capacitors which have :
- equal or higher ripple value
- equal or lower impedance value
- equal or higher voltage rating
- same capacity
- that fits into the area you have on the board

As you don't say where you live, I can't tell you where to buy from, but I'm going to default to US and suggest you to go here:

http://search.digikey.com/us/en/cat/...luminum/131081

There, you can pick 470uF, 25v, then sort by ripple value and look up the manufacturer and series of each capacitor that has higher ripple, lower impedance and would fit on your board.
If you're not in US, you can then look up those series on eBay or local stores.

For example, these will work:

http://search.digikey.com/us/en/prod...2388-ND/613749
http://search.digikey.com/us/en/prod...71B-ND/2504091

There are lots of models, but most are a bit higher than 16mm, so you also have to make sure they'll fit height wise.

[terry5880]

Re: my capacitors are different sizes (help)

thank you so much for your time and very quick responses i am from london uk post code se16

[mariushm]

Re: my capacitors are different sizes (help)

Ok, then you have Farnell and RS-Components.com

http://uk.farnell.com/jsp/search/bro...alues%3D202457

Then look for the ones that would fit (diameter and height), and look in the datasheet for ripple and impedance

These would work:

http://uk.farnell.com/rubycon/35zlh4...35v/dp/8126755
http://uk.farnell.com/rubycon/25zlh4...25v/dp/8126461
http://uk.farnell.com/nichicon/upw1e...ial/dp/1818631
http://uk.farnell.com/rubycon/25zl47...25v/dp/1144701
http://uk.farnell.com/panasonic/eeut...0uf/dp/1890539

the last one would be theoretically with higher esr/impedance but considering the quality of the chinese manufacturers and inflated specifications, I wouldn't worry too much about it. Anyway, the first ones are excellent choices.

[terry5880]

Re: my capacitors are different sizes (help)

so the 105c can be different as long as higher like 120c. im gonna see if i can find a shop close by as on that site it dont say where there shops are . 1 more thing the links above 1 says 10mm by 16 mm the ones i bought are 8mm by 16mm so thinking the ones already on board might be 10mm by 16mm as i think u said there is only 2 sizes ?

[mariushm]

Re: my capacitors are different sizes (help)

You can use any size you want, as long as the capacitors will fit in the room you have on the board.
You can also pick taller capacitors as long as they'll fit - you have a lid covering all those components, you just a couple of mm between the capacitors and the lid so you can go as tall as you think it's possible.

105c rated capacitors are the most common, along with 85c. There are 130c rated capacitors or higher than 105c, mostly for automotive use, but they can also be used for computers parts. The problem is these capacitors rated for higher temperature don't always have those high specifications.

Why would you care where the shops are? Farnell is pretty large, with warehouses and so on... it shouldn't cost you more than a couple of pounds to have them mailed to you within 1-2 days. If Farnell charges too much, check out RS-Components.com, they also have the location in UK.

The link for RS Components is this one : http://uk.rs-online.com/web/
And the capacitor page with the values you need already selected and sorted from best to less good is here:

http://uk.rs-online.com/web/c/passiv...Ripple+Current

[terry5880]

Re: my capacitors are different sizes (help)

ok ty i clicked on link at bottom of last comment then loads of capacitors can i use any of them . so sorry just dont wanna get it wrong as you said about the ripple and esr

[terry5880]

Re: my capacitors are different sizes (help)

also what is the M a at the end does that matter

[mariushm]

Re: my capacitors are different sizes (help)

M is a short code for tolerance, which is +/- 20%. Most capacitors are the value listed +/- 20%. So you can ignore that.

As for you previous question... are you even reading what I write?
I specifically told you that they're sorted already from what's best for you down to what would be not so good.
And you should already have some brains and use them when I already told you what you have to look for.

Take for example the first result from the list there in the link

Rubycon 35ZLK470M10X20
Rubycon Capacitor Al 105deg 470uF 35V 10x20

1. Is it 470uF ? YES
2. Is it 25v or higher? It's 35v, so YES

3. Will it fit in the space you have on the board?
It's 10mm wide so probably YES for diameter.
It's 20mm wide so you have to check - is there any component on the board that's 20 mm tall or higher? Is there 20mm between the board and the LID of that area? If yes, than YES
4. Is the ripple value equal or higher than the value of the old capacitor? 2880 mA > 1120mA, so YES
5. Is the impedance/ESR value equal or lower than the value of the old capacitor?
Click on the datasheet, scroll down to 35v chart because this capacitor is rated for 35v and select the 470uF value.... it says there Impedance 0.028 ohm
0.028 ohm is less than 0.060 ohm impedance, so YES.

ALL YES => THIS CAPACITOR WILL WORK

[terry5880]

Re: my capacitors are different sizes (help)

i am reading mate just all new to me so wanna get it right as i understand most what confused me isthe ripple and ESR as i dont know that of the ones already on the board that have blown not sure if 20mm will fit will check if not ill move to next 1 down thanks again

[terry5880]

Re: my capacitors are different sizes (help)

i still dont know how u can tell the esr and ripple of the ones that are already on the board the old ones sorry just confusing to me well that part anyway

[terry5880]

Re: my capacitors are different sizes (help)

I DONT KNOW IF THIS HELPS BUT IT SAYS ON THE BOARD e67640 94V-0

[mariushm]

Re: my capacitors are different sizes (help)

You said the capacitors on the board have the markings XUNDA and TM.
Xunda is the maker, TM is the series.

In one of the first posts, I gave you link to the list of products Xunda sells, which has a PDF there linked, with the title TM - that's the specifications for that capacitor. Here's a copy of that pdf, as the chinese site is slow:

Your capacitor is defined by the capacitance and voltage rating - 470uF and 25v. You go down in the datasheet and you find there the section where the voltage rating is 25v.
You than go down to 470uF and you have there two sections :



See the series on the top right?
See the voltage on top of chart ?
See the capacitance on the left of the chart?

You have two sizes for this capacity, each with its own ripple and impedance (ESR) values.
Your current capacitors are one of the two sizes.

[terry5880]

Re: my capacitors are different sizes (help)

ahhh ok so u could tell by the xunda and tm getting there thank you so much for your time mate