Are Nichicon HM & HN back in good standing?

[hardwareguy]

Re: Are Nichicon HM & HN back in good standing?

Hmmm..... we have intermittent shutdown and cranky power up on two machines.

They will be torn down and tested out the wazoo....its either HN plague extending a bit further than I thought or FSP snuck in some OST in the PSU.

[c_hegge]

Re: Are Nichicon HM & HN back in good standing?

Many of them appeared ok, but had high ESR readings. I don't have any here at the moment to fetch date codes from, but they would be circa 2006~2007. Next time I get one, I will note the date code for you. Most of them posted and ran, but were just quirky and unstable. Recapping them cured this.

I re-capped a Gigabyte GA-K8U-939 motherboard a few months ago. The four HM caps on the VRM in had '05 date codes. They weren't bulging, but I replaced them with Panny anyway (My rule is that they should be replaced if '05 or earlier). The main problem on this motherboard was the 5 Chemi-Con KZG on the VRM out, which were bloated and leaking.

[hardwareguy]

Re: Are Nichicon HM & HN back in good standing?

AH HA! I suspected something like that was up! The board may have been made in 2006...but the caps could be older. My finnicky Gigabyte Socket A boards are loaded with UCC KZG and 2003 dated HM.... gee I wonder why they are finnicky?

The first HMs I used for recaps were 2007 date code units and I think that's why they have been durable.

The only place I refuse to use them is the VRM sections in Dells, especially the Prescott boxes....its just so hot there for any 2000 hour cap. I poly mod those....its the only thing that really lasts.

[hardwareguy]

Re: Are Nichicon HM & HN back in good standing?

Our finnicky Socket 939 boards have Nichicon HM dated 2005, week 46 and UCC KZJ in the VRM....double trouble!

Ironically, the rest of the board is Rubycon MBZ. Really good caps everywhere...except the VRM.

[c_hegge]

Re: Are Nichicon HM & HN back in good standing?

Our finnicky Socket 939 boards have Nichicon HM dated 2005, week 46 and UCC KZJ in the VRM....double trouble!

Ironically, the rest of the board is Rubycon MBZ. Really good caps everywhere...except the VRM.

That's exactly what I found on my K8U-939. Rubycon everywhere except for the VRM where it's most critical. Gigabyte.

[linuxguru]

Re: Are Nichicon HM & HN back in good standing?

I've extensively used 3300/6.3 HM, date code 0532, on Vcore. No failures so far, everything running rock stable. My only problem now is that I'm running out of stock on these HMs - down to 8 pieces, which I'm conserving for something really critical, just like my stock of Panasonic FJ 1800/16 and FK 1500/6.3.

[Toasty]

Re: Are Nichicon HM & HN back in good standing?

The HM's I pulled out of the Abit SR7 I recapped and wrote about, were dated H0230 and H0136 and were perfect. Even the HD's (unsleeved) on VRM IN were fine.

I'd like to use HM's in some PSU re-works I'm doing. They'll be on the output filters. FM's and a few KZE's will be handling the other work.

Any opinions on this?

---------
I'm glad to see the topic has drawn some very helpful information out of the 'crowd'.

Gives me and hopefully others a better perspective and a larger base on which to draw conclusions on the use of these series'.

Toast

[c_hegge]

Re: Are Nichicon HM & HN back in good standing?

I think that they would be fine in a PSU. If Taiwanese caps like Cheapo Teapo can handle being in a PSU, HM probably would also, just as long as the date code is newer than 05xx

[PCBONEZ]

Re: Are Nichicon HM & HN back in good standing?

The HM's I pulled out of the Abit SR7 I recapped and wrote about, were dated H0230 and H0136 and were perfect. Even the HD's (unsleeved) on VRM IN were fine.

I'd like to use HM's in some PSU re-works I'm doing. They'll be on the output filters. FM's and a few KZE's will be handling the other work.

Any opinions on this?

---------
I'm glad to see the topic has drawn some very helpful information out of the 'crowd'.

Gives me and hopefully others a better perspective and a larger base on which to draw conclusions on the use of these series'.

Toast

My concern that 'radical' a departure from the original ESR is throwing the filters out of 'tune' [as it were] with the inductor.
Particularly on PI filters when you change the ESR on one cap a lot more than the other.
- Lets say on a full PI filter you drastically lower the ESR on the final out cap but leave the other cap and inductor ratings alone. - I've just encouraged more ripple to pass through the inductor to be shunted to ground by the cap with the drastically lowered ESR. On that side of the inductor the ripple can be felt by the load. [a.k.a. mobo].
[Recall the jonnyguru recap article were Ripple got worse with better caps installed, I think that's what happened there.]
.
Now, maybe that idea is all wet but that's why I don't change ESR any more than I need to in OP filters.
.

[i4004]

Re: Are Nichicon HM & HN back in good standing?

yes, i agree with bonez there...one should look at it as tuned circuit and any big changes in esr bring it out of tune.

offcourse, that's just one possible explanation (another one is settling-in wasn't allowed) and something else: more tests should be done to know for sure...test where one should measure ripple and esr of old stuff, then esr and ripple of new, and then draw some paralles etc.
we can't get the full story from one partial test on jonnyguru.
but like i said in other thread, i would aim for same esr as originals had.
(this offcourse assumes you know the esr of originals....if you have bluged caps it means you need to find some that are in better shape and measure thier esr)

[Toasty]

Re: Are Nichicon HM & HN back in good standing?

My concern that 'radical' a departure from the original ESR is throwing the filters out of 'tune' [as it were] with the inductor.
Particularly on PI filters when you change the ESR on one cap a lot more than the other.
- Lets say on a full PI filter you drastically lower the ESR on the final out cap but leave the other cap and inductor ratings alone. - I've just encouraged more ripple to pass through the inductor to be shunted to ground by the cap with the drastically lowered ESR. On that side of the inductor the ripple can be felt by the load. [a.k.a. mobo].
[Recall the jonnyguru recap article were Ripple got worse with better caps installed, I think that's what happened there.]
.
Now, maybe that idea is all wet but that's why I don't change ESR any more than I need to in OP filters.
.

Unfortunately with the JG(OW) recap, a list of what was there and what was used for replacement was not given. He did say that they had to scrounge around to get the caps.

Kind of makes me wonder if this had some effect on the "burnt coil" bit on the iMac thread. The coil being the surge limiter to the pi, as you stated. But, these have shown up failed prior to being recapped. I think his (nwd's) was too, just not noticed until loaded. Replacements pulled from good units got warm under moderate load but not unbearable. Underrated (current wise) coil IMO.

I always wondered why replacements used by many members were, from my perspective, caca. Using PW's where FM's would be so much better. .045/1440 vs. .018/2470 seems like a no-brainer to me. I had no problems with ripple on the Antec 450 or 350 I recapped. Both FM recaps from u-know-who brand.

That being said, I did use the same series on input and output of the pi. Not like I used an FC on in and FM on out. The thought occurred a while back about the ESR mismatch if I did so, but since I didn't and wasn't going to, it was 'shelved'. Then, 370 put up a post a few days ago about using poly's in the PSU outputs. It came down off the shelf and went back into the meat grinder. Then, while flipping burgers on the grille the other nite, it smacked me in the head saying 'you're gonna pull the ripple thru the lowest ESR cap', being the poly in that case. Then I came back and saw your post and I knew I was on the right track.

I think we need our engineers in here to 'splain it better, because up until now, an LC filter was calculated using capacitance and inductance. I don't remember current coming in there. Current was only of concern in RC filters to make sure a high enough wattage resistor was used.

Am I making any sense, or am I just nuckin' futz?

Toast

[i4004]

Re: Are Nichicon HM & HN back in good standing?

>That being said, I did use the same series on input and output of the pi.

i think oklahoma wolf did too.

coil?
it does make sense to mention coil too, as if indeed it's tuned circuit, and you swap both caps(with those with much lower esr), you should probably change coil too...

http://en.wikipedia.org/wiki/Capacitor-input_filter

you what would be fun? to put potentiometer above both of the caps, and then scope while varying the resistance...that would simulate different amounts of esr...

[hardwareguy]

Re: Are Nichicon HM & HN back in good standing?

I have had good luck using HM in a pinch in PSUs, but I change the caps in both sides of the pi filter. The characteristics of the circuit are certainly altered but I have had no issues.

I use PW on most PSU things, with the occasional HE and HV for the heavy duty stuff. (or hot box Dell SFF PSUs).

Chemicon LXZ is also a good one on PSUs.

[PCBONEZ]

Re: Are Nichicon HM & HN back in good standing?

We are both wondering the same kinds of things.

All the training I've had [and I think that's true for most people] regarding filters focuses on frequency, band-pass, capacitance, inductance and they use frequencies much higher than is applicable to ripple.

ESR is a TINY resistance with a BIG affect in the applications we see it in.
That makes the other TINY resistances that we are accustomed to disregarding significant.

If you consider that ESR is small and Xc huge at the ripple frequencies then ESR controls where the current goes and you can -sort of- use this as a equivalent circuit for ripple.

Remember the Inductor's value is large compared to the wires/connectors.

If you lower ESR too much on the right side, the cap to the left isn't doing anything.
Also pulls more ripple -through- the coil.
.

[370forlife]

Re: Are Nichicon HM & HN back in good standing?

If you lower ESR too much on the right side, the cap to the left isn't doing anything. Also pulls more ripple -through- the coil.

So what if you lowered ESR on both sides? What if ESR on the left side was lower, what would happen? Could you change the value of the inductor to help this out?

[PCBONEZ]

Re: Are Nichicon HM & HN back in good standing?

Could you change the value of the inductor to help this out?

What value?
- Ohms[ESR]
- Ohms[Real - As in DC]
- or uH?
They all matter for different things.
You could optimize the circuit for low Ripple and hose it for something else.
If you get too wild you may even make it oscillate.
And don't forget that when you first kick it on and the caps are 'empty' you basically have a different circuit.
-
That circuit has a uH to C balance going on - and
The voltage divider effect of the resistances and ESRs - and
what amounts to a different circuit when it first powers up.
- That's why futzing with values in filters is so messy.

So what if you lowered ESR on both sides? What if ESR on the left side was lower.

You know how to figure that out.
Parallel & Series Resistance equations and Ohms Law.

.
The small V drop on the run of wire gives some isolation between the OP filter and the board so ripple at the mobo end might be a bit different than at the PSU end.
Also remember that the return [ground] has many parallel wires so the return resistance is probably lower than the supply resistance.
.

I don't wanna figure all that crap out.
Easier to just find caps as close to the original values as possible.
.

[i4004]

Re: Are Nichicon HM & HN back in good standing?

370 here are some leads
http://www.google.com/search?rlz=1C1...ting+pi+filter

for example last post here
http://forum.allaboutcircuits.com/showthread.php?t=6514

but it surely is NOT as simple as ohm's law and parallel and series resistance...not at all.

but i agree with this
>I don't wanna figure all that crap out.
Easier to just find caps as close to the original values as possible.

ie why bother?

to put polys?
screw that.

[momaka]

Re: Are Nichicon HM & HN back in good standing?

Interesting (pages 5-9)...
https://cdn.badcaps-static.com/pdfs/...0a5b4a973d.pdf
I may have a brain fart here (not sure if my physics knowledge from this semester is any good at all since we didn't have a good teacher ), but the way I understood that article is that the filtering circuit of a PSU is an LRC-series circuit (where R would be provided mostly by the ESR of the caps). In that case, a resistance too high (high ESR) would make the circuit overdamped (which means less AC ripple current will be shunted to ground). With a resistance too low (very low ESR), the circuit would be underdamped and resonance/ringing may appear at the output. (see section 6 on Damping)
Perhaps this explains why caps with too low of an ESR may cause problems (as seen in that JG article).

[i4004]

Re: Are Nichicon HM & HN back in good standing?

yes momaka, i had somewhat simillar thoughts (without reading that article, though) here
https://www.badcaps.net/forum/showth...9897#post89897

it is a tuned circuit and changing values cannot be done by guessing, but in most cases they pull it off, because overall esr change is still small.

if it wasn't, and ripple was extremely increased, those low esr recapped psus would probably be burning hdds etc.

one should also know that some of the cheap psus have crappy pi filter to begin with, so they have much ripple in the tests when new....

[hardwareguy]

Re: Are Nichicon HM & HN back in good standing?

Well Ive recapped about 20 PSUs.... and done about half with Nichicon HM due to unavailability of PW in the size I needed or cost. (yes, HM is sometimes a LOT cheaper than PW...supply and demand at work!)

The performance was good on the scope on the few I bothered to check. I have this sneaking suspicion that the JG recap was done with caps with higher than stock ESR.

I'd have to see the equation to see how much the ESR actually changes things.