Replacing LCD CapXon Caps

[mariushm]

Re: Replacing LCD CapXon Caps

It's not quite the same thing, but for all intents and purposes you can use the Impedance value for the ESR.


To keep it short :

Capacitance needs to remain the same.
Voltage rating of the new capacitors should be the same or higher. Sometimes if you have no choice, you can use capacitors with lower voltage rating, but unless you know what you're doing you should never do that.
Ripple value of the new capacitor should be equal or higher. In the worst case if you have no alternative, it should be very close to the old capacitor's ripple value.
ESR/Impedance should be equal or lower. Very rarely, it "hurts" if the new capacitor's esr/impedance value is much, much lower than the original capacitor's value.

-

CapXon KF datasheet is here:

Basically you have :

220uF 25v 8x11.5mm , 550mA ripple, 0.15 ohm impedance/esr

1000uF 25v 13x20mm , 1650mA ripple, 0.045 ohm imp/esr

You say this last one is 10x21mm - there's no KF series capacitors at 1000uF/25v - the one matching this size is 820uF one. Perhaps this is not a KF series or you read the capacitance/voltage incorrectly?

So basically you go on element14.com, at the capacitors.

For the 220uF, 25v :

Check radial leaded,
check 8mm and the sizes that would fit in the space you have on the board (if 10 mm capacitors fit in there, check the size, repeat with larger diameters)
Check 220uF
Check 25v and values larger than that, like 35v, 50v - you can go up in voltage without any problems and capacitors with higher voltage rating have better specs but they're a bit larger.
Now click show products to get some results.

Now, from the left side, click on select manufacturer and click on Nichicon, then repeat the process with Panasonic, Rubycon, United Chemi Con - these 4 brands are quality ones.

Now, if you only selected 8 mm diameter, sort the results by price. Usually, better quality capacitors are more expensive but that's not always the case - if the stocks are limited, element14 increases the price. Still, it's a good start. If you can fit several diameters and you checked several, skip this step because you'll sort later by diameter.

From this point, if needed, check "In stock" from left side and press apply and the list should be smaller.

Now open one at a time and see which one has ripple value higher or equal than your capacitor's value and impedance lower or equal.

Here's my results page for the 220uF 25v:

http://my.element14.com/jsp/search/b...alues%3D202457

I picked 25v and 35v and 8mm and 10mm, only the quality brands, only what's on stock.

So from that page, as I selected both 8mm and 10mm diameter, I sort by the diameter to get the 8 mm ones first and then I check the datasheets for each result (there's a chart inside with voltage and capacity and the values for the combination) and find :

Panasonic HE , 220uF, 25v, 8x12mm , 640mA, 0.13 ohm ... about the same as your current one : http://my.element14.com/nichicon/uhe...ial/dp/1823642

Panasonic FM 220uF 25v, 8x11.5mm, 950mA ripple, 0.056 ohm better http://my.element14.com/panasonic/ee...25v/dp/1219468

Rubycon ZLJ 220uF 35v , 8x16mm, 1600mA, 0.059 ohm... even better if you can go to 16mm in height http://my.element14.com/rubycon/35zl...0uf/dp/1831280

... and there's others which you can pick fitting your need.... make a list and pick whatever's more convenient (price per quantity)

Now repeat what I said and make a list for the 1000uF capacitor (or 820uF, or another series... I don't know, there's no Capxon KF 1000uF at that size)

Paste here your selections for 1000uF and I (or others) can check if what you selected is good.

[biatche]

Hi,

I have this LCD monitor that uses

CapXon, 220uF, 25v, KF 105c, P552, VENT [11mm-*12*mm tall, 8mm dia]
CapXon, 1000uF, 25v, KF 105c, P546, VENT [21mm tall, 10mm dia]

So I read these are badcaps and so... please suggest what goodcaps to replace them with. I'd also like to mention this is the first time I'll be soldering and I'll need a soldering kit too... but anyway, just the caps to begin with.

I will be buying from http://my.element14.com and I'm very confused by impedance, ESR, Frequency Tolerance:..... some fields that are mentioned in one but not mentioned in the other...
I read that nichicon/rubycon are good.... but there's no exact match...

this appear to be the closest match http://my.element14.com/united-chemi...ial/dp/1690775
but I'm not sure at all.. because it has ESR specified.. while most don't.

Many thanks.