Nichicon HM - 0545 datecode

[Dan81]

So I've got this motherboard from a PC I bought for cheap.

It's an Gigaqbyte GA-8I848P, and I noticed it has Nichicon HM caps in the VRM which were known for their bad batch. Also the board came with a Pentium 4 3.00GHz SL7PM Prescott HT.

However, I have read that the bad batch had stopped production in 2004.\

My question is - are 2005 HM's safe? Or should I source some Rubycon MBZ and recap it?

[Behemot]

Re: Nichicon HM - 0545 datecode

I personaly ditch also 2005 caps even if test good as I have seen my share of bad ones. Keep them only since 2006.

Strange thing is, used Panasonic caps often have much lower than nonimnal capacity…

[Dan81]

Re: Nichicon HM - 0545 datecode

I personaly ditch also 2005 caps even if test good as I have seen my share of bad ones. Keep them only since 2006.

Strange thing is, used Panasonic caps often have much lower than nonimnal capacity…

So it's safe to keep them? I use a Prescott CPU so that's why I ask.

[Wester547]

Re: Nichicon HM - 0545 datecode

I would trust late 2005 dated Nichicon HM infinitely more than Chemi-con KZG. Not early 2005, but late 2005 for sure. Unless they test bad, I say keep them.

[Behemot]

Re: Nichicon HM - 0545 datecode

KZG are hit or miss, some work for ages, some not…replace them all anyway, just that they are somewhat erratic.

[Wester547]

Re: Nichicon HM - 0545 datecode

Rubycon ZLx are also known to lose capacitance over time. That said, I'd rather see the capacitance naturally drop than increase dramatically a la the failure-prone batch of Nichicon HM, HN, and HZ, which suggests that the thin layer of porous aluminum oxide covering the anodic aluminum foil is all but gone, probably due to weak or ineffective corrosion inhibitors, possibly contaminated electrolyte.

KZG do better in the VRM input than in the VRM output, but if you gave me a dollar for the number of popped KZG I and others have seen in the VRM output (E.G, the 3300uF 6.3V variants) and as general filters (E.G, 820uF 6.3V), even on lightly used or unused motherboards, we'd be very rich indeed. Same goes for KZJ (2200uF 6.3V in 10x16mm dimensions, for an example - those do very poorly), and the higher voltage ones don't do that much better. I don't consider them any better than GSC/Sacon/Evercon/Lelon/CapXon/Fuhjyyu/YEC/Teapo. The same could be said of TK ATWY/ATWB and Sanyo WF (and, since it concerns this thread, pre-2006 Nichicon HM/HN/HZ).

It's probably best to avoid HM, HN, and HZ made before 2006. But there have been exceptions.

[RJARRRPCGP]

Re: Nichicon HM - 0545 datecode

KZG are hit or miss, some work for ages, some not…replace them all anyway, just that they are somewhat erratic.

That's as long as you don't have KZGs bulging and leaking on a PC that's on the sidelines in the room...

Some of my KZGs were also bulging and leaking when my Asus A7N8X-X was unplugged!

[momaka]

Re: Nichicon HM - 0545 datecode

My question is - are 2005 HM's safe?

I'd say it's a bit of a coin toss - some are OK, some aren't. If you don't want to change them, check on them every once in a while. Nichicon HM/HN/HZ from that age tend to bulge pretty quickly once they start going bad. And more often than not, they tend to short-circuit temporarily. So you will know. If one goes bad, it's time to replace the entire batch on that board.

I had an interesting experience with a batch of 2005 Nichicon HZ (6.3V 2200uF) caps I pulled from one Xbox 360 motherboard. Found one bulged one in my parts bin a few years back. A month later, I found all of the Nichicon HZ 6.3V 2200uF caps from that same board were bulged. That said, all of my other 2005 Nichicon HZ 6.3V 2200uF caps I pulled from other boards are fine.

So occasionally, you may find some Nichicon HM/HN/HZ caps from 2005 to bulge. But for the most part, especially late 2005 datecode, they are OK.

And yes, I too would trust them more than Chemicon KZG. The only Chemicon KZG caps I've never seen failed personally are the 16V 1500/1800uF ones on VRM input of motherboards. The output 6.3V 3300 uF, as Wester547 noted, are notorious for going bad, as are the 6.3V 820uF ones.

[Behemot]

Re: Nichicon HM - 0545 datecode

Unless you feed the device with some Deer or similar crap, output part sees way greater load than the input, so that makes sense.

[Wester547]

Re: Nichicon HM - 0545 datecode

Yup, the VRM output capacitors, especially those without polymers in parallel, see a much higher ripple current (which is essentially AC current) than the VRM input capacitors. When a capacitor conducts ripple current (or when a capacitor is discharged), powerful electric charges move towards the cathode foil. This forms the cathode foil which can generate hydrogen gas if the ripple current is high enough (it's not dissimilar from reverse polarizing a capacitor, except it happens over a longer period of time). When a voltage is applied to the positive conductive plates of an electrolytic, the electric charges move towards the anodic foil. This does exactly the opposite: the higher the voltage and the lower the ripple current, the less chance of cathode oxide layer formation and therein gas development.

That said...

Electrolytics whose electrolyte contains bad chemistry, such as KZG and KZJ, can outgas and leak of their own accord, on the shelf, without any external potential and thermal duress. I and others have seen it happen enough times with KZG and KZJ to avoid them at all costs and replace them on-sight, even if they aren't guaranteed to misbehave like that.

As for why 2005 dated Nichicon HM/HN/HZ make me nervous:

They have a tendency to go bad (when they do go bad) the same way the 2001-2004 HM/HN do: high capacitance, high leakage current, possibly suggesting they have the same issue. And I've seen a surprising number of 2001-2002 dated HM in the VRM input of old Dell Optiplex / Dimension motherboards "last" (measure to spec with no visible deformation, IE the 1000uF 16V and 1800uF 16V HM) to this day, probably because they see a much lighter load than the output caps (IE, the 2200uF 6.3V HM) which always fail. So, if even some 2001-2002 HM are capable of lasting, of course those made in 2005 can last - but that doesn't mean they are entirely trustworthy. I suppose it is up to you whether to use them or not. Just don't be surprised if they fail of their own volition one day.