Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

[bw1]

Working on a Dell PowerEdge 400SC here.

The HN Spec Sheet doesn't list an 8x20mm with this capacitance and voltage, and I'm not confident enough to guess the numbers yet.

This computer is older and not worth a lot of time to me, but thought it worth the effort to check before it hits the scrap pile.

What are the guidelines when specs don't line up? There is only one 820uf @ 6.3v, so I don't have much else to directly compare it to.

Thank you!

[PCBONEZ]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Within a series the ESR and Ripple specs are locked-step with the can size.

In other words all 8x20mm HN will have the same ESR and Ripple rating.

All you have to do is look forget about uF and volts and look any 8x20mm HN.
.

[PCBONEZ]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

HN doesn't have many 8x20mm...

For a better illustration of the can size effects....
Look at all the HN 8x11.5mm Ripple & ESRs
Look at all the HN 10x16mm Ripple & ESRs
Look at all the HN 10x20mm Ripple & ESRs

Make sense now?


That method works within any series of good brand cap.

With bad brands it's hit and miss because some of them have screwy data sheets.
So sometimes with bad brands you have to interpolate a guesstimate.
.

[bw1]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

VERY good advice. I hadn't noticed that they were the same like that.

I'm having a heck of a time finding anything compatible in an 8mm diameter, and I think I could make 10mm work, but the 8 already is a tight fit, so it would be, well, reminiscent of the game Twister.

[PCBONEZ]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

I dunno who has what in stock but Mouser carries HN and I think so does badcaps.net.
You may also be able to find what you need in a polymer.
.

[bw1]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Looking at specs of similar caps, finding one with the same or higher ripple while keeping ESR/impedence is proving to be tough. There are a lot that have compatible cap/volt/esr, but not enough ripple.

Since 8x20 isn't listed on the sheets, this must be a custom HN, and I'm a bit stuck finding one that will work.

[yyonline]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

I managed to find some new old stock 8x25mm 820uF MBZs which work nicely for replacements of "extra tall" 820uF caps. They are either a custom or discontinued size, and appears on a lot of boards around 2004 or so.

Can you post a photo of the board including the location of the extra tall HN? There are some areas of the board, CPU VRM in particular, where capacitance is less important than ESR. If that's the case, I'd recommend replacing with 1500 or 1800uF to keep the ESR about the same. If the capacitor in question is not in the CPU VRM, then this does not apply.

[bw1]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Pictures attached.

[yyonline]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Those are CPU VRM caps. In that location, ESR is more critical than capacitance. So, stick with 8x20. Rubycon MCZ 6.3V 1800uF in 8x20mm is a good replacement:

https://www.badcaps.net/store/produc...products_id=36

You could also use polymer there:

https://www.badcaps.net/store/produc...products_id=76

I regularly replaced the extra tall 820uF with 1800uF before I found a stash of extra tall 820uF caps. I never had any issues.

A CPU VRM poly mod is also a frequently done modification.

[PCBONEZ]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Those 4 HN's are in Vcore. [At CPU voltage which is less than 2 volts.]
You could use 820uF 2.5v or 820uF 4v polymer there.
Common mod and 'stock' on slightly newer boards.

It looks like you may have some HM mixed in there too.
If so check the date codes.
2001-2004 HN and HM were defective.
-
H0322 - I dunno
H0322 - year 2003
H0322 - week 22
.

[bw1]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Fujitsu polymers look like ESR is 7, but it looks like the original is 12 - is that correct? If so, acceptable?

[PCBONEZ]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

In Vcore that is totally acceptable.
In fact it's a common mod and a very well proven upgrade.
.
Make sure they will fit... like 8mm vs 10mm.
Use same diameter as the old ones so the leads are spaced correctly.
- Just makes life easier...
.

[bw1]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

[bw1]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Hey - are those polymers a pretty universal swap for CPU VRM use?

I've got another Dell board here that I just noticed has one of 8 slightly starting to bulge. 820uf 4v Chemi-Con KZV's. Can't see a reading on the pair of yellow's, other than their ratings. I'd probably leave them alone?

[PCBONEZ]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

The yellow ones are Fujitsu Functional Polymer [FPCAP] which are a hybrid between wet electrolyte and solid polymer.
Functional [aka Hybrid] polymer have a layer of polymer on one plate but they still have liquid between the plates.
Some of the Fujitsu 'bumble bees' from early production had occasional [uncommon] issues with the seal but your board is newer than that.
Since then they have been as good as solid polymer.
[Most people don't even know they aren't solid polymer.]
Fujitsu recently sold that product line to Nichicon who changed the cans on some versions but they still call them "FPCAP".
They may even have left the name and made them true solid polys when they changed cans.

---
Okay. - Some educapacation for sake of no confusion..
[And the following applies to socket 478 vintage and up.]

A VRM has two 'sides'.
-
The 'in' or 'high' side has caps connected to PSU on +12v. [P3 can be +5v or +12v, older is +5v]
The VRM-in caps are almost always 16v caps.
These caps are all in parallel.
-
The 'out' or 'low' or 'Vcore' side has caps on the CPU's core voltage.
Since P3 no PC CPU has had a Vcore voltage over 2 volts.
These caps are also all in parallel.
-

To do a successful VRM mod you need to keep a minimum total capacitance in both VRM-high and VRM-low.

You also must understand that not all polys are created equal and you need to make sure you don't accidentally raise the total ESR by a poor cap choice.
[IOW: Some polys have ESR that is worse than some lytics.]

-And- the number of caps used in the VRM affects what you can/should do.
One VRM might have 6x very high end lytics while another has 12 low end lytics. - That effects what polys should be used.

The ancient VRM wisdom is that you can lower uF by 1/2 if you lower the ESR significantly.
In general that's true but if you have high end electrolytics with higher uF values there may be no 'room' to lower the ESR enough to matter.

I found another way to figure it out.. Here goes..
-
Socket 478, 775, 771 all have the same cap requirements in the VRM so by looking at many newer 775 boards from many manufacturers with all poly VRMs as original we can make an educated guess about what the minimum uF can be and about what ESR should be.
-- I've did that & the conclusions:

- VRM-low
At least 5500uF for a warm fuzzy
- Some cheap boards get by with 4800-5000uF
- 5000-6500uF is typical.
- Better 775 boards & 771 server boards tend to have 6500uF or more.]
Total ESR should not be more than .001 ohms.
- try to get it between .0009 and .0005 with under .0008 being the warm fuzzy zone.
[[ This works for the ESR math: http://www.1728.com/resistrs.htm ]]
ALSO, check the total ESR on the old ones to insure you don't raise it.

- VRM-high
3x 470uF/16v -or- 4x 330uF/16v is the norm.
[That's enough uF but a little more uF there would harden the system somewhat against momentary power surges tripping it off-line.]
Total ESR should not be more than .003 ohms & warm fuzzy below .0025 ohms.

If you do this right you'll have warm fuzzies all over the place!
.

That's all the theory.
As for the board in you pic.....
-
Your VRM-high has 4x Rubycon ZL. Those are good, I wouldn't bother there.

VRM-Vcore already has 2x560uF FPCAP and has 8x other positions.
You could use polys in 560, 680, or 820 uF. [820 is almost over-kill.]
As long as their [individual] ESR is .010 ohm or less it should be fine.
.

[bw1]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

You know, for a Grumpy Old Fart you sure are helpful...

I've been gone for the last few days, so just getting back into things again.

So it sounds like the poly's mentioned earlier should work just fine, as they are 820uf and less than .10 ESR (around .07, I believe.)

I've got another board here with a 680uf 4v (8mm x 8-ish) TMV series (Chemi-Con, I believe???) poly that I haven't had ANY luck finding the specs on. There are some mentions from 2007 on the forum here that people were having trouble with info, but I didn't see anything useful. The board is an ASUS P5GD2-X, and had bad 16v KZG's and the polys almost all look slightly rounded as well. I should only need help with the TMV's. Do you have any information on these?

I attached a picture from google images of the board - not actual board I have here but same model. If I'm supposed to start a new thread for each motherboard I have questions about, let me know.

Thanks!
-bw1

[PCBONEZ]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Appears to be a custom ordered size that only came in one or a small few sizes.
They don't list custom orders in their catalog so no data sheets.
I don't think they are polymer.
All Chemicon's polymers begin with a 'P' last I checked.
And on small caps sometimes they skip the vents.

Use the thumb-rules I gave for Vcore caps earlier and it will be fine.

I would be more worried about those KZG's,, but then again for all I know the TMV is a custom sized KZG... So ???

There was also a TMZ about that time which I think only came in one or two sizes and no data sheet exists.
People questioned if they were fake until I came across this in an ad.
.
.

[bw1]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

Yeah the KZH's are all very much bulging, but I think I've got that one figured out. I don't have time to look at the small ones right now, but I might be back with questions yet.

[PCBONEZ]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

I'm getting lost..
Where did KZH come from?
Are we on the same board?
.

[brethin]

Re: Specs for Nichicon HN 820uf/6.3v, ***8x20mm***

He changed boards. Yes bw1 make a new thread for each board so things don't get hard to find and follow.