UCC KZG Replacement

[Cyclone121]

ASUS A8N-LA version 2.0 (HP/Compaq Nagami 5188-5067)
Socket 939 (Athlon 64 X2 & 4GB DDR)
nVIDIA GeForce 6150 LE/nForce 430 chipset
Yes, an old board, but it works for a shop PC, it's plenty quick & has legacy hardware I need, plus SATA & PCI-e x 16 -- best of both worlds...you can buy them on eBay all day long for less than $40.
I bought mine refurbished couple/three years ago to replace dead AGP board & it came w/ two replaced United Chemi-Con KZG 6.3V 1500uF caps...

Now several 6.3V 820uF have burst or bulged & it won't POST, so I'm going to recap all 25 remaining KZGs, which I've read on Badcaps have high failure rates, maybe especially in high heat applications (a tight desktop case in a dusty shop, yep it's warm, even with a slot fan)...any remaining large caps are Panasonic.

They used a Panasonic a FJ 6.3V 1500uF and a FR 10V 1500uF when refurbishing (a little odd, but OK, what they had on hand).

Do you see any problem with using all Panasonic FR to replace:

14 @ 6.3V 1500uF, 10 @ 6.3V 820uF & 1 @ 16V 470uF
All are 8mm w/ 3.5mm lead spacing

The impedance (~ESR) of KZG vs. FR on the 1500s is close:

.026Ω (KZG) vs. .030Ω (FR)

The 6.3V 820s however are a bit apart:

.036Ω (KZG) vs. .056Ω (FR)

The 6.3V 1000 uF FR is same at .056Ω, on a 1200 uF it drops a little: .041Ω

Same issue with 16V 470uF:
.036Ω (KZG) vs. .056Ω (FR)

What I like best about the FRs (besides the price and easy availability) is 105° C @ 6000 hrs. vs. 3000 hrs. for Panasonic FM, though ripple current is lower & impedance is higher w/ FRs

Are those specs really that critical on a 10-year-old motherboard? The FR has very respectable numbers & are very reliable I'm told...

[momaka]

Re: UCC KZG Replacement

Do you see any problem with using all Panasonic FR to replace:

14 @ 6.3V 1500uF, 10 @ 6.3V 820uF & 1 @ 16V 470uF
All are 8mm w/ 3.5mm lead spacing

The impedance (~ESR) of KZG vs. FR on the 1500s is close:

.026Ω (KZG) vs. .030Ω (FR)

The 6.3V 820s however are a bit apart:

.036Ω (KZG) vs. .056Ω (FR)

The 6.3V 1000 uF FR is same at .056Ω, on a 1200 uF it drops a little: .041Ω

Same issue with 16V 470uF:
.036Ω (KZG) vs. .056Ω (FR)

Looks like FR should be okay for all of the caps here.

Typically, it's the caps around the CPU and any inductors / toroids / coils that you want to match with same or better capacitors. The rest are generally not so critical in terms of specs, particularly caps around PCI/PCI-E/AGP slots (almost anything can be used here sometimes).

According to pictures of your motherboard I found on the net, most of those tall 1500 uF capacitors are indeed around inductors around the CPU, Nothbridge, and RAM. But for those caps, the specs of FR matches reasonably well, so they should probably work okay.

As for the 6.3V 820 uF caps, looks like most of those are around the back ports (i.e. probably used for filtering for USB or the like) and some around the Southbridge. Either way, most of these shouldn't be under high stress, so again FR will likely work fine without causing any issues, despite not having the same specs. That said, if height permits, feel free to use 1000 or even 1200 uF caps in place of some of those 820 uF caps.

And finally the single 16V 470 uF cap - that probably for filtering the 12V rail on PCI-E connector... so FR should be more than fine for that too.

What I like best about the FRs (besides the price and easy availability) is 105° C @ 6000 hrs. vs. 3000 hrs. for Panasonic FM, though ripple current is lower & impedance is higher w/ FRs

Well, this only matters more if the caps are running in a very hot environment (which in this case may qualify, since you say these motherboards are used in a dusty shop). That said, a cap that can handle higher ripple current will heat up less than one with a lower ripple current rating. Thus, even though those FM caps have only 3000 hours endurance, they will heat up less when stressed with higher ripple current. And when they heat up less, their endurance increase. Thus, it is possible to have an FM cap last as much as FR.

But I am just stating this as a "fun" technical fact. You need not worry about this too much when it comes to recapping this particular motherboard.

Are those specs really that critical on a 10-year-old motherboard?

Sometimes they are, yes. It really depends on the circuit design of each motherboard model, though.

The FR has very respectable numbers & are very reliable I'm told...

Panasonic/Matsushita capacitors in general are extremely reliable (if not the most reliable from all Japanese brands). It's rare to see one popped for not reason. If you do, then better check that either the circuit is functioning properly or that the cap was installed the right way.

[Cyclone121]

Re: UCC KZG Replacement

Thanks very much for your thorough reply, it gives me a lot to work on & better understanding of motherboard layout & the importance of ripple current rating.

I will look over DigiKey & Mouser again to see just what are my options...low-ESR, high-ripple, 105C caps are quickly disappearing ("out of stock", yeah) -- I suppose wet caps' days in consumer electronics are dwindling.

I don't know if I can trust eBay, there may be reliable sellers, but for the relatively small amount caps cost, why penny-pinch? Still, .50 per cap is getting pretty steep...

I'll decide between FR & FM & uF values & let you know how it comes out.

[retiredcaps]

Re: UCC KZG Replacement

I don't know if I can trust eBay, there may be reliable sellers, but for the relatively small amount caps cost, why penny-pinch? Still, .50 per cap is getting pretty steep...

There is a NY seller that has Panasonic FR and FM 820uF 6.3V for $0.20 cents each. "$2 First Class USPS Shipping on All Orders in the US! Priority Service is Available". I have purchased from seller before and he sells the genuine capacitors. For the 1500uF 6.3V, he has no Panasonic, but Nichicon HZ.

I get no kickbacks, money, etc for mentioning this. I brought it up just you can save a bit of $$$.

Also, if you didn't know badcaps.net has store that sells capacitors, but after a quick look, TopCat, the owner here doesn't stock 820uF 6.3V and doesn't sell Panasonic at all, although he has tried to source Panasonic. If TopCat did sell Panasonic FM/FR, I wouldn't even have posted this message.

https://www.badcaps.net/store/

Your search skills should find the Rochester, NY seller that is selling "Panasonic FM $0.20".

[retiredcaps]

Re: UCC KZG Replacement

Yes, an old board, but it works for a shop PC, it's plenty quick

Too bad, the top CPU is X2 4800+ on this board.

The PC I'm using is a Compaq that I got for free. It had a X2 3800+, but I managed to get a X2 6000+ for $5 CDN so I upgraded this PC. Of course, I'm stupid for using a 6000+ during summer time. I'm sure during winter, it will make a nice foot/feet warmer.

I'm finally making the transition to 64 bit OS and apps as there is talk in the Linux world that 32 bit distros will be gone in the 3 to 5 years. As such, before I decide to fix an old motherboard, I check out the supported CPUs. If I can get a 7 or 8 year old top of the line dual core CPU for $5, then I will fix the old motherboard.

Dual core CPUs are fast enough for my simple everyday needs. Most of the time, they run at throttled down CPU speeds by the cpu governer in linux to save energy and generate less heat.

[Cyclone121]

Re: UCC KZG Replacement

I appreciate the tips -- in future I won't neglect to include photo(s) of the board -- it didn't occur to me it would be all that helpful to see the board, as I've already decided to replace all the KZGs & some have already burst, but I didn't consider where the caps are on board is important (e.g., yes, the 470 uF 16V apparently is there to condition the 12V rail for a PCI-e video card). And I didn't want to waste space on his server.

I've been visiting Badcaps for years as a passive viewer, and often read the troubleshooting tips, they are very helpful, obviously.

I looked over the caps in TopCat's store before I originally posted -- yes, top brands, reasonable shipping -- but it was lack of suitable 820uF 6.3V which sent me searching elsewhere. The Rubycon ZLH available has lower ripple & higher resistance...I also looked at Cap King near Cincinnati, but no good fit.

The CPU on the A8N-LA is a X2 4400+ (ADV4400DAA6CD) Toledo 90nm, 2.2GHz, 2x1MB L2 cache, 1.3V, 89W TDP which I picked up on eBay cheap -- I need to run Windoze (64-bit), but the 4400+ handles it acceptably, multitasks fine, a solid 939 chip, cool running (mid-30s), not bad for a decade-old processor. The Radeon HD 6570 1GB video card helps make it bearable. Premium OCZ 500w power supply seems to be going strong after a Thermaltake 430w failed & took the old AGP board with it. Agreed that 4-6-8 cores are largely under- or unused by most users & software.

I couldn't find the Rochester, NY dealer mentioned today, though I'm sure I've bought from him in the past...

So, I ended up at Mouser, they had Panasonic FM at 820uF/6.3V & 470uF/16V which are really close on ESR (.005Ω) & are higher ripple-rated.

I had to select FR for 1500uF/6.3V, but it's same deal: 5 milliohm ESR difference but much higher ripple than UCC KZGs.

With USPS & tax it was still a bit less than $20.

I've attached a few photos, more for practice than anything...my latest phone's camera is better than any other I've owned, but still not that great. Hope they're acceptable.

[momaka]

Re: UCC KZG Replacement

I looked over the caps in TopCat's store before I originally posted -- yes, top brands, reasonable shipping -- but it was lack of suitable 820uF 6.3V which sent me searching elsewhere. The Rubycon ZLH available has lower ripple & higher resistance...

Despite not being on par with UCC KZG, Rubycon ZLH still have pretty decent specs. In fact, I just used some 6.3V 820/1000 uF Rubycon ZLH caps last month to recap an Asus P5GC-MX motherboard that was also full-to-the-top of Chemicon KZG.

I've attached a few photos, more for practice than anything...my latest phone's camera is better than any other I've owned, but still not that great. Hope they're acceptable.

More than acceptable. The quality of your photos is quite good.

Just for future reference, though... when you post photos of any circuit board (be it a motherboard, power supply board, or whatever else). it is usually a good idea to also include a picture taken straight from top above the board. That way, if it's a complicated circuit that requires troubleshooting, people can see what goes on in the circuit more easily. As for this thread, this is obviously not needed, since your motherboard just has some bad KZG caps - which your pictures capture beautifully .