is cap size important

[Undead]

I know that in a lot of cases you can't go over a given size for caps because they won't fit in the space, but does a slightly smaller height matter?

I am mostly using Panasonic caps now. The last monitor I opened up has caps (470uF 25V) that are about 10 dia x 18L, and the Panasonic ones I have are about 2mm shorter. Will this have any adverse affect or should I try to find another brand with identical dimensions?

I am wondering if one or more have been replaced at some point as there are 5 caps with the same stats, and 3 different lengths. (a blue one with the same specs is about 17L)

[selldoor]

Re: is cap size important

It would help if you told us what make and series you were replacing and where - power supply? Ideally you should check the esr and ripple on the
datasheets for the caps you are replacing and match or better them.
Chances are if you are using Panasonic FR FM or FC they will be better than
what is in even if 2mm shorter.

[Undead]

Re: is cap size important

My apologies I thought it was a generic type question, I will add the requested info ASAP.

Ok 2 of them look like Ltec LXY, there is also a PET marking.

2 others have no manufacturer shown, they are brown and have a KZE shown, and one shows ON and the other OG.

The last one is blue, looks like Ltec as well and has LZG and the PET marking.

They are for the power supply board in a Viewsonic VX1940w LCD monitor. If necessary I can try to find a camera to upload pics.

The Panasonics I use are FR FM or FC's. (in this case the ones I have are FM and FC, I have both so could use either)

[Undead]

Re: is cap size important

Can anyone confirm this now that I have added the requested info?

[brethin]

Re: is cap size important

Cap size (physical dimensions) does not matter as long as it fits.

[ratdude747]

Re: is cap size important

Cap size (physical dimensions) does not matter as long as it fits*.

Fixed: * -assuming that the ESR is close... Can size often changes the ESR for a given Capacitance and voltage within a Particular series. Usually it isn't enough of an issue to cause problems but it is something to be aware of.

[Undead]

Re: is cap size important

Thank you all very much for your responses.

[Undead]

Re: is cap size important

Original Ltec caps that could be identified

LZG impedance 0.060
LXY impedance 0.038

replacement Panasonic

FM impedance 0.026
FC impedance 0.068

So are the FC caps close enough to use or would the low impedance FM's be better? I would like to use all the same ones if possible. I'm not sure how much difference would be acceptable to replace something with.

[brethin]

Re: is cap size important

Fixed: * -assuming that the ESR is close... Can size often changes the ESR for a given Capacitance and voltage within a Particular series. Usually it isn't enough of an issue to cause problems but it is something to be aware of.

zzzbhm

[ratdude747]

Re: is cap size important

zzzbhm

And your point is?

[Undead]

Re: is cap size important

Anyone?

How close is "close"? As close as possible or as long as it is within a certain range of the original?

[selldoor]

Re: is cap size important

For the purpose of this repair I would just use Panasonic FM for all if that is what you have.

[Undead]

Re: is cap size important

Thank you again.