Different size caps can affect the ESR, ripple current handling, reliability and cost of a capacitor.

Making a capacitor smaller for a given voltage/capacity tends to negatively affect at least one of the 4 above factors.

My observations:

1. Super crappy capacitor manufacturers WAAAAAAAAYYYYY overrate their capacitors. They are crap and don't last very long.

2. Quality capacitor manufacturers rate their capacitors properly.

What is the brand of the capacitor on the motherboard?
What is the brand of the capacitor on the video card?

BLockOUT wrote:

i was trying to replace a 560uf 4v capacitor from a motherboard […]
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i was trying to replace a 560uf 4v capacitor from a motherboard

then i saw a videocard with the same cap. took it out and the videocard capacitor is almost twice the size of the motherboard one. ( that was a solid capacitoron both)

then i noticed other capacitors electrolitic on other electronic
components. thatwere not motherboards

caps are almost twice the size . same rating ..same voltage...and SAME height

why is that? how come some are really big and some are small and thr height is the same

Please have a look at the example specs of LOW ESR Panasonic FR series
https://industrial.panasonic.com/cdbs/www-dat … BA0000C1022.pdf
As you can see from above, say size 10x25 has ESR 0.018, 16x25 is 0.014 (both available in same voltage rating) so this is not huge leap in ESR difference, but the bigger is rated almost 1000mA higher than the smaler size in ripple current specs. So size mostly is determined by ripple current (and ESR in some cases). Not everytime on voltage though, see 1000uF capacity for 16V and 50V and check available sizes. Word of advice: stick to reputable brand (Panasonic, Nichicon, Chemicon, Sanyo, Samsung). I've given just an example, but from my experience Jamicon is an absolute minimum, and even this may be subject to discussion.

Just a small correction - Sanyo's semiconductors are now made by Suncon. Still good stuff, though.

gdjacobs wrote:

Just a small correction - Sanyo's semiconductors are now made by Suncon. Still good stuff, though.

Oh, didn't know about this. I got and old supply still branded as Sanyo. Good to know.

Never ever reuse capacitors. It just isn't worth it. New ones are cheap and easy to find. Always buy low ESR ones and you'll be golden 😀

krivulak wrote:

Never ever reuse capacitors. It just isn't worth it. New ones are cheap and easy to find. Always buy low ESR ones and you'll be golden 😀

No. Some caps require higher ESR when they're in a feedback loop. Without it, the circuit won't stabilize. Caps on output pi filters and motherboard buck converters can generally be of lower ESR, but in general the replacement caps should have a similar ESR to what was used before.

gdjacobs wrote:

krivulak wrote:

Never ever reuse capacitors. It just isn't worth it. New ones are cheap and easy to find. Always buy low ESR ones and you'll be golden 😀

No. Some caps require higher ESR when they're in a feedback loop. Without it, the circuit won't stabilize. Caps on output pi filters and motherboard buck converters can generally be of lower ESR, but in general the replacement caps should have a similar ESR to what was used before.

I guess it would be pretty difficult to have a precise esr without the motherboard schematics because those installed could be already bad for measuring.

You can normally find the datasheets for most capacitors, and work out the correct ESR/ripple current from that.

Then cross-reference it to a different series to find a suitable replacement capacitor.

Normally, exact ESR isn't terribly important, because electrolytic capacitors have pretty large error margins, but you do want to match as best you can.

Unless you know they're not in a feedback loop. Then you can go nuts with ultra low ESR and get crazy ripple suppression.

hi guys thanks for the feedback. well i guess im out of luck
i went to an electronic store and asked for 2200uf 6.3v caps
seller told me they only had low esr, and the price was too high. so i bought only 3.

the motherboard is actually SoYo branded and the caps are a mess. but look how small and thin the low esr caps i bought , compared to the original ones.

i guess i will have to continue searching on another store non low esr? the brand on the ones i bought are Jackon

You may need to polymod that motherboard.

Ultra-low ESR electrolytic capacitors aren't really made anymore as motherboard manufacturers have shifted to polymer solid electrolytic capacitors.

All depends on the actual model of the motherboard though. Do you have that?

BLockOUT wrote:

hi guys thanks for the feedback. well i guess im out of luck
the motherboard is actually SoYo branded and the caps are a mess. but look how small and thin the low esr caps i bought , compared to the original ones.

i guess i will have to continue searching on another store non low esr? the brand on the ones i bought are Jackon

Jackon is an upgrade from the old Sacon's (Almost everything is better than Sacon. They have ruined many graphics cards over the years...), but I wouldn't use Jackon either. It's not a good brand.

I often use Panasonic FR on motherboards (High quality but not expensive. Rated for 6000h @ 105 degrees celsius, low ESR). There are caps that can handle more ripple current, but usually it's not needed (when replacing the common 1000uF 6.3v Teapo or Tayeh caps for example).

that is a big difference between "NON ESR" caps and "ESR" caps.

ESR are always smaller? In your case can you use the smaller capacitors or not?

The big difference between general purpose capacitors and low ESR capacitors is significant for high frequency circuits.

General Purpose capacitors have a higher resistance to charging and discharging, meaning under high frequency loads, they heat up, perform worse, and fail sooner.

Low ESR capacitors have a lower resistance to charging and discharging, meaning much better performance for high frequency PC power supply circuits. Of course, this doesn't account for the fact that badly made LOW ESR capacitors will overheat and fail quickly.

canthearu wrote:

Low ESR capacitors have a lower resistance to charging and discharging, meaning much better performance for high frequency PC power supply circuits. Of course, this doesn't account for the fact that badly made LOW ESR capacitors will overheat and fail quickly.

On a motherboard (or graphics card), low ESR caps can almost always be used (But don't guess, check the specs for the old ones before replacing).

However, in a PSU you should not use low ESR caps unless the old ones are low ESR as well. The circuit was (hopefully) designed with these caps in mind, and a lower ESR can cause problems in a switched PSU.

edit: I would also not recommend replacing electrolytic caps with solid ones as some people do. Use caps that the board was designed for.

Ageve wrote:

On a motherboard (or graphics card), low ESR caps can almost always be used (But don't guess, check the specs for the old ones before replacing).

However, in a PSU you should not use low ESR caps unless the old ones are low ESR as well. The circuit was (hopefully) designed with these caps in mind, and a lower ESR can cause problems in a switched PSU.

On a motherboard, they are usually high performance low ESR or ultra low ESR caps. You can usually polymod these without too much problem.

Power supplies generally use low ESR capacitors as well, but usually do not need as low an ESR as motherboard caps. Getting replacement caps for a power supply is generally not a problem though, places like mouser, element14 and rs-online still sell suitable caps. Do NOT try doing a polymod of an ATX power supply, most of the time, they don't really like it. In fact, you will find that virtually all capacitors in a power supply will be low-ESR, except for maybe a few of the smaller value caps (smaller than 10 uF) and the big primary side capacitors. Generally I find that the primary side capacitors rarely cause problems, so very rare that you would need to replace those, while the small secondary side caps can be replaced with low ESR capacitors and won't substantially effect the circuit.

This is what I have learned from checking out and fixing many PSU units with bad capacitors, with quite a good success rate. I try and catch these problems before the device fails completely and requires more extensive repair.