DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

[jesscat606]

Hey guys,

I've got a G4S600-B (this board) that has about 2 dozen UCC KZG caps on it. This is in a digital audio encoder used at a radio station, so it's been on/powered pretty much 24/7 for a number of years. recently it's been getting flaky, so I pulled it apart and noticed that 7 of the 16 1500uF caps on the board are bulged. Did some more research, (signed up for this board!) and find that the KZGs are pretty much despised here.

So I'm looking to recap the motherboard. The KZGs on it are all 6.3V, 105degrees:


1500uf 8x20mm marked 5(7) 7S- 10
1500uf 10x20mm marked 6(7) 6G - 4
1500uf ~10x12mm marked 6(k) 8E - 2
470uf ~5x11mm marked 5(k) 6c - 3
470uf ~5x11mm marked 5(k) 6V - 3

I'm assuming that I ought to replace the 470uf caps too?

(EDIT: looks like all the rest of the on-board caps are Nichicon HM(M) or OST RLG)

I'm looking through Digikey, most of what I'm seeing is Nichicon/Panasonics/Rubycon. I'm not very knowledgeable on ripple currents, esv, etc., so I'm hoping someone on here can help me out with some compatible replacements. Here's where I'm looking:


I've never seen a MB with this many popped caps!

Thanks guys,

-J

[trshaner]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

The Panasonic FR series is a good choice for switching regulator applications such as on this motherboard.



Just make sure the diameter and lead spacing will fit and the same or higher working voltage.

There is a known issue with the Chemicon KZG capacitors. More info here:

https://www.badcaps.net/forum/showthread.php?t=30329

Ripple current and high-ESR is what caused these caps to fail.

[lti]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

Nichicon HM series is a direct replacement, and HN and HZ series have lower ESR. I think any of those three series would work.

The 470uF caps in the second picture are KY series, which don't need to be replaced.

Are you sure they are all rated for 6.3V? The larger 1500uF caps might be rated for 16V.

[trshaner]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

Along with low ESR you want a capacitor with a high Endurance rating. The Panasonic FR series is now rated 5,000 hours at 105° C. Most are listed as 2,000 hours at 105° C.



Choose a cap that has a 105° C 'Lifetime @ Temp' or 'Load Life' rating of 5,000 hours or higher if you're looking for long service life.

BTW - I worked at the manufacturer of your motherboard (DFI-ITOX) for 7 years. We and many other MB manufacturers had a slew of MB returns due to bad caps. Flatscreen TV manufacturers were also affected.

[kc8adu]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

i use polys in those.
the ones i fix from harris hdradio exporters seem to have had a rough life.

[jesscat606]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

Nichicon HM series is a direct replacement, and HN and HZ series have lower ESR. I think any of those three series would work.

The 470uF caps in the second picture are KY series, which don't need to be replaced.

Are you sure they are all rated for 6.3V? The larger 1500uF caps might be rated for 16V.

Hey, thanks! I wondered about the 470s. All the Chemicons are 6.3V; the 16v ones are all OST.

The HM/HN/HZ don't have the failure issues the KZGs do?

[jesscat606]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

i use polys in those.
the ones i fix from harris hdradio exporters seem to have had a rough life.

Yeah, this one is a BE xpi10 HD Radio exporter - looks like it needed some TLC; I've already replaced a flaky PSU on it. I'm guessing the polys have higher heat tolerance? do you have any recommendations for poly replacements?

[jesscat606]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

Along with low ESR you want a capacitor with a high Endurance rating. The Panasonic FR series is now rated 5,000 hours at 105° C. Most are listed as 2,000 hours at 105° C.



Choose a cap that has a 105° C 'Lifetime @ Temp' or 'Load Life' rating of 5,000 hours or higher if you're looking for long service life.

BTW - I worked at the manufacturer of your motherboard (DFI-ITOX) for 7 years. We and many other MB manufacturers had a slew of MB returns due to bad caps. Flatscreen TV manufacturers were also affected.

Thanks! I was talking with the manufacturer of the unit (who used the dfi-itox board), and they were saying they had a lot of those units come in with this problem. wanted $2000 to replace the MB - apparently the working stock of these is really low!)

[mockingbird]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

The lifetime rating on the Panasonic FR is meaningless in this application, in the sense that if the Panasonic FR capacitor is meant to withstand all the ripple of an ultra-low ESR cap, it's lifetime rating wll probably be equal to or less than the ultra-low ESR cap. Moreso, FR has a lower ripple rating (not to mention that it will also get hotter because of its higher ESR), so it could last significantly less time.

You should use HM/HN/HZ. You mentioned you were looking at Digikey. They may or may not have what you need in an electrolytic cap. You might try doing a polymer re-cap.

Since this machine seems to be from 2006, it's robably worthwhile to have a look inside the PSU to check if the caps in there are OK. That way, you can order both the motherboard and PSU caps together and save on shipping.

[jesscat606]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

You should use HM/HN/HZ. You mentioned you were looking at Digikey. They may or may not have what you need in an electrolytic cap. You might try doing a polymer re-cap.

Since this machine seems to be from 2006, it's robably worthwhile to have a look inside the PSU to check if the caps in there are OK. That way, you can order both the motherboard and PSU caps together and save on shipping.

Yeah, this is an old machine. as I had noted above, I had already replaced the PSU with a new one a number of months ago...wasn't looking for cap problems at the time, so didn't notice them.


Several people have mentioned going with polymer caps. I dunno much about them - would something like this work?

EDIT: Oh, wait, that's SMD - not the right mounting style.

Digikey doesn't seem to have the HM/HN/HZ caps, you're right.

[mockingbird]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

1500uf 8x20mm marked 5(7) 7S- 10
1500uf 10x20mm marked 6(7) 6G - 4
1500uf ~10x12mm marked 6(k) 8E - 2
470uf ~5x11mm marked 5(k) 6c - 3
470uf ~5x11mm marked 5(k) 6V - 3

I think you meant those 4 caps were 16V, not 6.3V. So for the 16V 1500uF caps, here are the choices:
this, this, or this. (Nichicon HM/HN)

If you want to experiment with polymer, this, or this should work, maybe even overkill.

For the 10 6.3V 1500uF capacitors:
this, this, this, this, or this.

Polymer:
this, this, or this.

For the 2 short 1500uF caps:
this, or this.

Polymer:
this, this, this, or this.

[jesscat606]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

i think you meant those 4 caps were 16v, not 6.3v. So for the 16v 1500uf caps, here are the choices:
this, this, or this. (nichicon hm/hn)

if you want to experiment with polymer, this, or this should work, maybe even overkill.

overkill? I note that those are 1000uf, not 1500...is there a reason this is ok, other than that's the nearest size Digikey has? (I'm not tied to digikey, I'm just more familiar with them.)

for the 10 6.3v 1500uf capacitors:
this, this, this, this, or this.

Polymer:
this, this, or this.

these are all 2.5v, not 6.3v. The only 1500uf/6.3v/8mm polys i saw were smd.

for the 2 short 1500uf caps:
this, or this.

Polymer:
this, this, this, or this.

Those look like they would work.

Are there any likely problems or concerns with mixing poly/non-poly caps on a board? I like the extended life of the polys, but don't wanna cause issues.

-j

[mockingbird]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

overkill? I note that those are 1000uf, not 1500...is there a reason this is ok, other than that's the nearest size Digikey has? (I'm not tied to digikey, I'm just more familiar with them.)

Because when you replace VRM high caps, you usually use polymer equivalents with a much much lower capacitance. This has mainly to do with the fact that 16V polymers don't go very high in capacitance, especially at 8mm. Since yours are 10mm, I chose 1000uF to be safe, eventhough you can probably use as low as 270uF here.

The reason that you can get away with this on the VRM high, is that with the VRM high, low ESR and high ripple are important, and not bulk capacitance, or at least that's what I have been told.

these are all 2.5v, not 6.3v. The only 1500uf/6.3v/8mm polys i saw were smd.

Pentium 4 VCore is less than 1.5V. That's why 2.5V is more than sufficient on the VRM low. If you bought 6.3V ones in 8mm, you'd just be spending a whole lot more money for no reason.

Are there any likely problems or concerns with mixing poly/non-poly caps on a board? I like the extended life of the polys, but don't wanna cause issues.

Nope. At least not in your case.

I've done it myself. I have an Asus P5B I use almost on a daily basis. For the VRM high, I used ordinary Nichicon HM, and for the VRM low, all UCC PSC 2.5v 820uF polymer caps.

[jesscat606]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

So, I picked up the Panasonic polys, just got them...and the leads are 1.2mmm wide - and won't fit the holes. Returning them and will likely go with the HMs - which have 0.6mm leads.

[c_hegge]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

^
Really? Which ones did you get? The leads on all polies I've seen have been the same 0.6mm as HM.

[RJARRRPCGP]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

wanted $2000 to replace the MB

Bullshit!!

You can get a 5960X with an X99 motherboard for less than that!

[jesscat606]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

^
Really? Which ones did you get? The leads on all polies I've seen have been the same 0.6mm as HM.

Actually, I need to retract that last. I was thinking the leads were too big; what happened was I was getting leftover solder in the mounting holes, not letting me get the new caps in. which is being a real PITA, because these caps mount on a huge copper plate (on both sides of the board!) and it's almost impossible to heat it long enough to use my solder sucker.

Bullshit!!

You can get a 5960X with an X99 motherboard for less than that!

Yes, well, this is in an HD Radio encoder; it's got a custom, proprietary linux build that expects all the IRQ / PCI / Northbridge / Southbridge / CPU settings of this motherboard.

So I'm pretty much stuck with this specific motherboard. Which, since it's long since discontinued, is horrifically expensive.

[jesscat606]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

Bam!

Now to see if it will boot back up. Here's hoping I didn't screw it up!

[c_hegge]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

Looks good! The caps all look like they are installed correctly. Fire it up and see how it goes.

[mockingbird]

Re: DFI-ITOX G4S600-B with Chemicon KZGs - compatible caps?

Nice job! Any reason you chose not to replace the 5 or so 6.3mm OST caps, most of them near the northbridge?