Replacing cap with different values

[idobi]

Hi,

I just bought a new video card on eBay and when I received the package I noticed a disconnected cap. I don't live in the US so I didn't want to start a long return procedure, so I decided to let my local electronics lab replace the cap.
They did a great soldering job but when I got home I noticed that the new cap has completely different values:
Original cap - 16v 330uF
New cap - 25v 1000uF

Is this a problem? Will my card function correctly? Will it damage the card in the long run?

Thanks in advance!

[Rainbow]

Re: Replacing cap with different values

It should work fine.

[idobi]

Re: Replacing cap with different values

Thanks for the quick reply!

[whiz]

Re: Replacing cap with different values

How do we know that? the new capacitor is way to big than the older...

sorry Idoby if that scares you but i don't think it's ok and you should ask them why they used a bigger capacitor! Rainbow you didn't even ask idoby what kind of video card he has!!?!

[PeteS in CA]

Re: Replacing cap with different values

Do you have a specific concern, whiz?

[willawake]

Re: Replacing cap with different values

no point to stock every size of cap in the repair shop.

why not tell us what is written on the cap or take a pic of both sides and we will tell you if its good or not.

[tiresias]

Re: Replacing cap with different values

Original cap - 16v 330uF
New cap - 25v 1000uF

Hi idobi,

I'll agree with whiz in that you should first assess what that capacitor's function is on that video card. You would be using a component whose capacitance would be over 300% of that which you are replacing, after all.

The voltage rating is not a problem, component size aside.

But I can't claim expertise on the subject, so you'll have to ask one of our resident electronics gurus.

[arneson]

Re: Replacing cap with different values

I would think if card works properly, the after effect would be good, not bad.
That should be a reasonable repair.

My 2 cents are totally worthless and should be eliminated.

[yanz]

Re: Replacing cap with different values

if it is an old card, the caps may be on 3.3v or 5v.

tiresias, yes that's a 300% upgrading but it's only 1000uf. if the cap is for bulk capacitance or filtering, i sometimes replace the original 680-1500uf caps with the 2200uf or the (extremely higher) 3300uf ones with no problem.

usually on an old card, you may find two type of caps, one with lower value (100-330uF caps) and another one with the higher value (>1000uf caps). i would say for the former type, 1000uf is the highest limit but is safe to use. anyway, what can it hurt?

the smaller ones usually placed before the vrm chips. cmiiw.

[whiz]

Re: Replacing cap with different values

Do you have a specific concern, whiz?

Are you getting offencive? i'm Greek i don't understand!

question:
Does Rainbow knows idobi's video card? if yes... then i'm sorry!
if not...he CAN'T have opinion if the cap is ok to be bigger or not!

@willawake the original cap was 330μF do you think it's difficult to be found?
they are repair shop (as you said...) they are obligated to have the needed replacement components!
They didn't repaired the board they modified it by using components (probably) out of manufacturer's specifications...

that is my humble opinion and it is not need to be 100% correct!
for once again SORRY idobi i don't mean to scare you! it is VERY possible all are fine if the board works!


P.S capacitor's Voltage i think it is not so important if it is higher than the previous...(if it is lower it might be a problem too!) again this is my opinion.

[yanz]

Re: Replacing cap with different values

most of member here have experiences that they can use a (silghtly) bigger capacitance if they didn't find the exact match for caps they want to recap.

also, by observing the card/hardware sometime we can make assumption that 2x or 3x bigger replacement is okay. it's hard to find the case where placing a bigger caps can hurt, except in the psu (auxiliary part).

imho, it's different than violating the manufacturer specification, as long as we know what we do <- the knowledge that many times comes from the experiences. well, even in my places (industrial city), most of electronick shop just dont have all the goods you need. you sure need to be creative..

[Rainbow]

Re: Replacing cap with different values

Increasing capacitance of electrolytic caps raraly hurts. 330uF -> 1000uF is 3 times more but 1000uF is not that much.
On some boards you can find many 330uF caps all around while there are 1000uF instead on some other ones. Manufacturers usually use the lowest (cheapest) values that still works properly.

[desertdragon]

Re: Replacing cap with different values

I think there's a mistake. The technician must install 3 pcs of 1000uF in series ckt.

[willawake]

Re: Replacing cap with different values

@willawake the original cap was 330μF do you think it's difficult to be found? they are repair shop (as you said...) they are obligated to have the needed replacement components!

no it would be an unnecessary expense to keep every value of cap in stock just so the customer can be happy that exactly the same value was used as replacement, usually the customer only cares that the product is working properly again and the repair cost was kept down.

They didn't repaired the board they modified it by using components (probably) out of manufacturer's specifications...

if they exceeded manufacturers specifications then i would consider that a bonus.

everybody is missing the point. what brand/series of cap did they use as replacement. was the original cap low esr and the replacement cap also similarly low esr?

[Rainbow]

Re: Replacing cap with different values

Completely useless discussion... The important question is: does it work?

[arneson]

Re: Replacing cap with different values

Completely useless discussion...

Ok then, get ready for a three page'r.

The video is upside down, the cap is really warm, something is glowing,
I'm hearing voices, how long Will this last? (not the card, the thread.)

[PeteS in CA]

Re: Replacing cap with different values

Are you getting offencive? i'm Greek i don't understand!

Whiz, your previous post seemed arhumentative, so I asked for more information to check my impression. I'm happy to see I was mistaken, and I appreciate your being willing to communicate in a language other than your native Greek. English is not the easiest language in the world, but don't let it scare you.

Folks here are pretty technically aware. The issues in substituting values are the capacitance, the rated voltage, the ESR, the can size, and the temperature rating. Obviously, the new part fit, so can size wasn't an issue. Substituting a 25V part for a 16V part is safe, provided the ESR isn't significantly increased. By using the higher capacitance, the ESR was probably about the same as, or lower than, the original part. If the original part was rated for 105C, I can't imagine the repair shop using an 85C rated part. An increase in capacitance isn't too critical, even with the O/P cap for a switching regulator, as typical tolerances for the critical components, the C and the inductor, are typically +/-20 or +/-30%, and designers allow for this very wide tolerance, and also allow for significant load capacitance. If this part is used in the I/P of a switching regulator or in a linear regulator, the increase is not a concern.