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**Stefan Payne** · 01-31-2016, 02:58 PM

Re: Recapping of Corsair VS450

Pls take a look at the series used...

A 'CapXon' cap can be anything from a 'GP' KM series, to a high end FH series...
Same with the other caps...

It's important to get the ESR value right...

Besides:
Do you want to do it because of fun and learning or do you want to 'improve' the PSU?
If you don't want to do it just for fun, it may be better to buy a new, better PSU because it's cheaper...

Because those caps aren't that cheap. You can expect about 10€ for all of them, besides the primary one...
That one alone costs about 2,5€/piece...

Besides: 180uF/400V caps are something found in rather small PSUs in the 300W range...

**omega** · 01-31-2016, 03:17 PM

Re: Recapping of Corsair VS450

Sorry I forgot attaching the pics of the PSU.

Originally posted by Stefan Payne View Post

It's important to get the ESR value right...

The trouble is that most of the specifications omits just the ESR.
Anyway the CapXon series is GF except for the 12 rail, which is KF.
Yes, I am aware that good caps are rather expensive, but Momaka encouraged me to repair this PSU.
As regards the motivation of recapping, I explained it in another thread about Technoware recapping.

Attached Files

**goodpsusearch** · 01-31-2016, 03:48 PM

Re: Recapping of Corsair VS450

Nice. Definitely worth recapping.

The caps are just low esr. You can use Rubycon YXG, Panasonic FC, FK, Nichicon HE, Chemicon KY etc.

Are you sure the -12V has 1x Capxon 2200uF, 16V???

Isn't it 220uF?

**mariushm** · 01-31-2016, 04:10 PM

Re: Recapping of Corsair VS450

Chemicon KZE or KY, Nichicon HW , Panasonic FM or FR will work great.

I wouldn't use Panasonic FC simply because there's better capacitors out there for about the same price.

Don't go with ultra low esr, don't go with too high esr... get something close to the Capxon's esr but don't stress yourself too much, the design of the power supply is not that great to require such "special" capacitors.

As for -12v, what you use there doesn't matter much .. 220-470uF, anything will work. It's only used for serial communication nowadays (if your motherboard has the header and connector) and pretty much any device will accept voltages in the range of -13v .. -10v , they won't care about accurate voltage on -12v.

**omega** · 02-01-2016, 03:07 AM

Re: Recapping of Corsair VS450

Originally posted by goodpsusearch View Post

Are you sure the -12V has 1x Capxon 2200uF, 16V??? Isn't it 220uF?

Difficult to read the value of this cap, even with a knife blade as a mirror. I will be confident once I desolder.
Thanks for your support!

**TELVM** · 02-01-2016, 01:24 PM

Re: Recapping of Corsair VS450

Originally posted by omega View Post

1. is the capacitance of the filter big cap high enough (180uF), or should I consider (if it is possible) to increase it?

180uF for a 450W PSU is on the low side of capacitance (bulk caps are relatively expensive, the VS450 is a budget PSU, and they've penny-pinched on this), but it isn't mission critical.

If you're in the mood and there's room for a larger bulk cap, a 330~470uF of higher 420~450V voltage rating wouldn't harm (though I'd better invest first on improving the secondary caps).

Originally posted by omega View Post

2. how is it possible to put together caps of different voltages besides different capacitances as I saw in some rails of this PSU?

For +3.3V you may see from 6.3V to 10V or 16V caps (and combinations of them).

For +5V, from 10V to 16V caps.

For +12V and -12V, from 16V to 25V caps.

For +5VSB output filtering, from 10V to 16V.

Within reason, the higher the voltage rating, the less stressed the cap will be and the longer it will last.

**goodpsusearch** · 02-02-2016, 04:19 AM

Re: Recapping of Corsair VS450

Originally posted by TELVM View Post

180uF for a 450W PSU is on the low side of capacitance (bulk caps are relatively expensive, the VS450 is a budget PSU, and they've penny-pinched on this), but it isn't mission critical.

If you're in the mood and there's room for a larger bulk cap, a 330~470uF of higher 420~450V voltage rating wouldn't harm (though I'd better invest first on improving the secondary caps).

For +3.3V you may see from 6.3V to 10V or 16V caps (and combinations of them).

For +5V, from 10V to 16V caps.

For +12V and -12V, from 16V to 25V caps.

For +5VSB output filtering, from 10V to 16V.

Within reason, the higher the voltage rating, the less stressed the cap will be and the longer it will last.

I wouldn't increase the primary capacitors C too much. 330uF should be more than enough.

6.3V caps are good for 5V too if you have space issues

**TELVM** · 02-02-2016, 12:36 PM

Re: Recapping of Corsair VS450

Originally posted by goodpsusearch View Post

I wouldn't increase the primary capacitors C too much ...

Why not?

**mariushm** · 02-02-2016, 01:31 PM

Re: Recapping of Corsair VS450

One good reason... the inrush current could kill the fuse in your power supply or in your house's panel, or the bridge rectifier in extreme cases.

A power supply with such a low input capacitor won't have anything to limit the current flowing into the capacitor so you'll see probably 20-30A pulled for a few milliseconds.

Going from 150uF to 330uF won't make much of a difference but way higher values could do bad.

A lot of capacitance won't make much of a difference in day-to-day use of the power supply. Above a certain value it doesn't matter.

You'd only want to increase the primary capacitance if you want the power supply to respect the atx standards, as in have enough capacitance to stay on if there's no mains power for one AC cycle, which would be 1000ms / 50 Hz = 20ms if I remember correctly at full load.
But I think it's rare that you'd have such drops in the mains power and you won't use your power supply at full load... chances are if the mains power is unreliable, it will be unreliable for more than just one ac cycle.

**TELVM** · 02-02-2016, 03:19 PM

Re: Recapping of Corsair VS450

Originally posted by mariushm View Post

... the inrush current could kill the fuse in your power supply or in your house's panel, or the bridge rectifier in extreme cases ...

Agreed, but the VS450 comes OEM with a NTC thermistor to limit inrush current:

...A lot of capacitance won't make much of a difference in day-to-day use of the power supply. Above a certain value it doesn't matter ...

"... Problem is with those (primary) caps being so small, the transistors have to work in overdrive to put more current through the transformer to keep the output stable. They usually don't manage it so you see 600~1000mVp-p of ripple on the output in a 100Hz sawtooth wave. See this picture from a "430W" PSU with 350W load. It used 680uF primaries, predicting 340W max output... and the ripple is already through the roof:"

https://www.badcaps.net/forum/showpo...&postcount=445

**goodpsusearch** · 02-02-2016, 03:23 PM

Re: Recapping of Corsair VS450

APFC boosts voltage

Q=C*V

So, if the V is higher you get away using lower C primary caps.

Of course this cap is on the low side. But there is no need to follow rule of thumb that says:

total primary C = Psu max W

This only apllies to NO PFC or Passive PFC units

330uF is more than enough. He should pay attention that the Voltage is 420V or 450V

**TELVM** · 02-02-2016, 03:33 PM

Re: Recapping of Corsair VS450

1110uF of primary caps for 1000W of APFC PSU: http://www.jonnyguru.com/modules.php...tory5&reid=459

**goodpsusearch** · 02-02-2016, 03:37 PM

Re: Recapping of Corsair VS450

An exception.

**momaka** · 02-03-2016, 07:50 PM

Re: Recapping of Corsair VS450

Originally posted by omega View Post

While I am not 100% confident of the respective rails...

If you want us to confirm, it is best to put pictures both of the top side and solder side of the PSU. For the top side, do not zoom in too much. A picture like the one TELVM uploaded in post #11 is good.

Originally posted by omega View Post

My purpose is to replace every cap with the IDENTICAL ones but of good quality (and low ESR in the secondary zone), any suggestion?

For CapXon GF:
Chemicon KYB (preferably), KY, or KZE
Nichicon HE (preferably) or HD,
Panasonic FK (preferably), FR, or FM
Rubycon ZLJ (preferably), ZL, or YXG

For the rest, you can use the capacitor series in the above list as well as these:
Chemicon KYA, LXV, LXY, and LXZ
Nichicon PW, PS, PM, PJ, and PV
Panasonic FC
Rubycon YXJ

Originally posted by omega View Post

1. is the capacitance of the filter big cap high enough (180uF), or should I consider (if it is possible) to increase it?

It's probably big enough for 300 Watts or so. Shouldn't be a problem with just about any basic computer that doesn't have a power-hungry video card.
That said, the bulk cap in your PSU is non-Japanese brand, and non-Japanese brands do seem to fail more often on PSUs with APFC (usually, it takes some time, though). So if you are replacing it, you might as well get a cap with slightly bigger capacity. 220 to 330 uF would be more than enough.

Of course, those big caps are usually expensive (relative to the cost of other caps for the PSU). So I'll leave that decision up to you here. Chances are, that PSU will last at least several years with the bulk cap that's in there right now.

Originally posted by omega View Post

2. how is it possible to put together caps of different voltages besides different capacitances as I saw in some rails of this PSU?

The voltage rating of the capacitor just needs to be higher than the voltage on the rail that it is going to filter. (Typically, 25% higher or more is an okay margin, and 50% is a very safe margin.) So for the 3.3V and 5V rails, it is possible to use 6.3V, 10V, and 16V caps. For the 12V rail, however, you must use at least a 16V -rated capacitor. 25V will work too.

Originally posted by omega View Post

Difficult to read the value of this cap, even with a knife blade as a mirror. I will be confident once I desolder.

Indeed it can be sometimes.
The easiest thing to do is to number each cap and make a "cap-map" as you remove them one-by-one. You can do that digitally (on the computer with Paint, Photoshop, etc.) or by hand on paper. Or, as you remove each cap, note down its specs (voltage, capacitance, brand, etc.) and then see which designator number on the board (i.e. C15, C20, Cxx, etc.) it corresponded to, then write down the info on paper.
That way, you won't get lost when all of the caps are removed.

**Stefan Payne** · 02-04-2016, 09:26 AM

Re: Recapping of Corsair VS450

Originally posted by momaka View Post

For CapXon GF:
Chemicon KYB (preferably), KY, or KZE
Nichicon HE (preferably) or HD,
Panasonic FK (preferably), FR, or FM
Rubycon ZLJ (preferably), ZL, or YXG

[/quote]
I wouldn't use KY as replacement for the new CapXon GF.

The Impedance of a 2200uF/16V CapXon GF is about 0.022.
KY is about 0.043 Ohms, wich would be a great replacement for the KF series.
KZH and KZE would be fine though...

Don't have datasheet for the others. But if my mind isn't wrong, the Panasonic FR and FM aren't the best choice due to rather high impedance.
But I have to look those values up.

**stj** · 02-04-2016, 10:26 AM

Re: Recapping of Corsair VS450

FR esr for 2200/16 is 0.018ohms
FK is 0.025

**momaka** · 02-04-2016, 03:49 PM

Re: Recapping of Corsair VS450

Originally posted by Stefan Payne View Post

I wouldn't use KY as replacement for the new CapXon GF.

The Impedance of a 2200uF/16V CapXon GF is about 0.022.
KY is about 0.043 Ohms, wich would be a great replacement for the KF series.

Have a look again.

KY @ 16V 2200 uF (12.5 x 25 mm can) has 27 mOhms ESR and 2230 mA RC. I would say that is reasonably close to the CapXon GF specs for the same 16V 2200 uF size.

I should also say I made my recommendation based on the 6.3V 2200 uF CapXon GF and not the 16V version. If you read post #3 again, according to omega, his PSU only has CapXon KF on the 12V rail. Every other CapXon is GF series.

So for the 6.3V 2200 uF CapXon GF, specs are 37 mOhms ESR and 1720 mA ripple for the 10 x 25 mm can.
Chemicon KY with same capacity and voltage rating: 42 mOhms ESR and 1650 mA of ripple. That's reasonably close. But, if you re-read my post, you will see that I put "preferably" next to the KYB series, which have 37 mOhms and 1650 mA of ripple current for the same cap - an almost spot-on replacement for that particular CapXon GF cap.

Originally posted by Stefan Payne View Post

Don't have datasheet for the others. But if my mind isn't wrong, the Panasonic FR and FM aren't the best choice due to rather high impedance.

No, FR and FM have even lower ESR than KZE. About the same class as KZH and KZM, which is more or less between motherboard grade and PSU grade.

**goodpsusearch** · 02-04-2016, 03:58 PM

Re: Recapping of Corsair VS450

Momaka you rule!

**omega** · 02-04-2016, 04:11 PM

Re: Recapping of Corsair VS450

just as a curiosity: how can you be so accurate with ESR values? I read from you that you can guess milliohm! My dear Blue ESRmeter does not go beyond centiohm :-(

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Recapping of Corsair VS450

Recapping of Corsair VS450

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