NCC KZGs really that bad?

[TheLaw]

I'm seeing a lot of motherboards using KZG theses days. It seems that people are bagging on KZGs on this forum, and I was wondering if it's really that bad or not...

Just curious to hear your opinions.

[PCBONEZ]

Re: NCC KZGs really that bad?

Yes

[TheLaw]

Re: NCC KZGs really that bad?

Yes

So OSTs or KZGs. =P

[PCBONEZ]

Re: NCC KZGs really that bad?

If =P means POS then yes.
.
It's bad enough when caps go bad,,, but caps that go bad -and- 'look' perfectly fine suck 10x more.

If you have a board that won't run and it's got bloated caps then you can be fairly confident a recap will fix it and you aren't wasting your time.

OST, KZG, KZJ, and TAYEH will go bad in mass and the board will 'look' perfectly fine.
That isn't to say they never bloat BTW. Sometimes they do.

TAYEH kinda faded away. Only seen on older boards.
.

[TheLaw]

Re: NCC KZGs really that bad?

Oooohh, those devils. I see what you mean. I was just curious. It would seem to me that if a manufacturer is willing to buy from a reputable brand like NCC, then why would they pick the crap cap versus the decent one, like a KMG. I suppose KZGs are cheaper than KMGs or Nichy HNs or something?

Well thanks.

[Colt45ws]

Re: NCC KZGs really that bad?

I have a 2.5 year old Biostar board that failed its KZGs. Only one of them popped but the others are toast as well, Im sure. Though, I think its kinda weak on caps to begin with. 3 1500uf on the VRM input and 4 3300uf on the VRM output for a 3.2 prescott. So its probably pretty rough on caps regardless.

[PCBONEZ]

Re: NCC KZGs really that bad?

I have a 2.5 year old Biostar board that failed its KZGs. Only one of them popped but the others are toast as well, Im sure. Though, I think its kinda weak on caps to begin with. 3 1500uf on the VRM input and 4 3300uf on the VRM output for a 3.2 prescott. So its probably pretty rough on caps regardless.

Yeah that is kind'a light with 4x3300uF.
There's enough uF there [8x or 9x 1500uF isn't too uncommon on 'prescott boards'] but I can't see 4x lytics having low enough total ESR.
If you have some empty cap pads then you might wanna add some caps.
[Make sure the pads are in parallel with those 4 caps.]

The VRM-in should be okay if those three are better grades like MBZ up.

.

[Colt45ws]

Re: NCC KZGs really that bad?

Yeah that is kind'a light with 4x3300uF.
There's enough uF there [8x or 9x 1500uF isn't too uncommon on 'prescott boards'] but I can't see 4x lytics having low enough total ESR.
If you have some empty cap pads then you might wanna ad some caps.
[Make sure the pads are in parallel with those 4 caps.]

The VRM-in should be okay if those three are better grades like MBZ up.

.

I was hoping to be able to add a cap or two, but no additional cap pads.
Its getting MCZs in the input and MBZs on the out.

[PCBONEZ]

Re: NCC KZGs really that bad?

Oooohh, those devils. I see what you mean. I was just curious. It would seem to me that if a manufacturer is willing to buy from a reputable brand like NCC, then why would they pick the crap cap versus the decent one, like a KMG. I suppose KZGs are cheaper than KMGs or Nichy HNs or something?

Well thanks.

Nichicon HM and HN were defective from 2001 thru 2004 due to a manufacturing error.
That one got in the news big time and I think some mobo mfrs are still 'gun shy' about using them.

KMG don't have that low of ESR.

KZG are comparable to MBZ, FJ, FL, WG, HM for ESR & Ripple.
KZJ are comparable to MCZ and HN.

What amazes me is that the motherboard manufacturers never figured out KZG had a problem.
They are out of production now [so I hear] but they were made for ~years~ and most mobo mfrs used them at one time or another.
I'm thinking the failure rate during the warranty period was low enough they didn't care.
[Same same with OST.]
.

[PCBONEZ]

Re: NCC KZGs really that bad?

I was hoping to be able to add a cap or two, but no additional cap pads.
Its getting MCZs in the input and MBZs on the out.

If you can get MCZ for the 'out' I would do that.
There aren't enough cap pads to go to Polys.

[Colt45ws]

Re: NCC KZGs really that bad?

Hmm, okay, Ill try to get a hold of some. They are difficult to find. Only one place I have found has them and they are out of stock.

[mockingbird]

Re: NCC KZGs really that bad?

KZG is batch dependent IMO... They're all lousy, but some batches preform better than others. Right now I'm typing from a Soltek motherboard with KZGs around the CPU... I'll recap it, but It's been running nearly 24x7 for months now with few problems.

I'm sure if I test them, they'll all read half capacitance. Still, a step up from OST.

[PCBONEZ]

Re: NCC KZGs really that bad?

My first experience with the KZG issue was two systems with the same board that worked fine one day then simply wouldn't boot the next.
They died one day apart. [As if I didn't have enough to do.]
None of the caps were bloated but I heard here that KZG were going bad.
[It was new news at the time].
-
One had KZG/VRM-in and MBZ/Vcore.
The other had MBZ/VRM-in and KZG/Vcore.
-
I didn't want to wait for caps just to see in they were repairable at all so I pulled the MBZ off one and made the other one all MBZ.
- Fired right up and ran fine.

Ordered caps and fixed the other one later. It worked too.
.

[PCBONEZ]

Re: NCC KZGs really that bad?

Hmm, okay, Ill try to get a hold of some. They are difficult to find. Only one place I have found has them and they are out of stock.

With only 4 caps there you want as low of ESR caps as you can get.

These have lower ESR than the original KZG and are comparable specs wise to each other.
Rubycon MCZ
Nichicon HN
Samxon GC

Lower ESR still are..
Nichicon HZ
Samxon GA

My preference would be MCZ but that's just me.
HZ would probably be my second choice.
.

[c_hegge]

Re: NCC KZGs really that bad?

...It would seem to me that if a manufacturer is willing to buy from a reputable brand like NCC, then why would they pick the crap cap versus the decent one, like a KMG. I suppose KZGs are cheaper than KMGs or Nichy HNs or something?

KMG are not suitable for motherboard use, which is why manufacturers don't use them. Their ESR is too high. The reason manufacturers use them over rubycon for example is because they don't seem to realise that KZG is actually worse than some taiwanese beands. They think that KZG is as reliable as rubycon. All they need to do, though, is read these forums.

[Agent24]

Re: NCC KZGs really that bad?

OST, KZG, KZJ, and TAYEH will go bad in mass and the board will 'look' perfectly fine..

Interesting - I've got an Albatron board, Intel 865 Chipset, won't POST and it's full of KZG (although flat-topped).... sound hopeful for repair?

[PCBONEZ]

Re: NCC KZGs really that bad?

Yes it does if there is no obvious other damage.

Inspect your chipset closely to make sure there is no sign of overheating.
[Shiny spots mean it got hot there. Also might present as cracks or pits.]
Take a look for the same thing on the MOSFETS.
- If you don't see any problems there then go for it.
The odds are pretty good.
.

[TheLaw]

Re: NCC KZGs really that bad?

KMG are not suitable for motherboard use, which is why manufacturers don't use them. Their ESR is too high. The reason manufacturers use them over rubycon for example is because they don't seem to realise that KZG is actually worse than some taiwanese beands. They think that KZG is as reliable as rubycon. All they need to do, though, is read these forums.

Really? My set top box has KMGs and I've seen LOTS of motherboards use them. Hmmph...

[Agent24]

Re: NCC KZGs really that bad?

Yes it does if there is no obvious other damage.

Inspect your chipset closely to make sure there is no sign of overheating.
[Shiny spots mean it got hot there. Also might present as cracks or pits.]
Take a look for the same thing on the MOSFETS.
- If you don't see any problems there then go for it.
The odds are pretty good.
.

The board looks in very good condition, MOSFETs look fine, both NB and SB look fine.

The only thing visually 'wrong' is that some of the VRM capacitors have strange marks on the top, as if very tiny snails had been going around on top of them.

I don't know what caused it but I think that will make sense to you as I suspect you will have seen some like that before.

[c_hegge]

Re: NCC KZGs really that bad?

They can be OK as the small 100uF caps without vents on motherboards where the ESR isn't so critical, but they are general purpose caps, NOT low ESR.