AOpen AK79D Max

[Operandi]

My current machine is running on an AOpen nForce2 based board; the CPU is feed by the 5v rail if that's relevant. The board is rock solid but has two caps that appear to domed at the top (probably been this way for awhile); two of three Lelons.

There is a similar post by the wonderfully helpful Oklahoma Wolf on these forums referring to the AK79G with the only difference being integrated graphics. Like his board the rest of the caps appear to be Chemicons.

According to OW's thread the Lelon cap specs are as follows: Lelon RXA 10v 10mm 3300uf. What would be a good replacement for these? OW replaced his with 12mm Panasonic's I believe but if possible I'd like to get something in the original 10mm in size.

I should also state this will be my first attempt at re-capping anything, thought's and suggestions appreciated.

[gonzo0815]

Re: AOpen AK79D Max

Youz can use some Rubycon MCZ or MBZ, all are availiable in 10mm, 3300uf 6,3v. But UCC KZG and probably Samxon GD should be aviliable too at those specs.

[Operandi]

Re: AOpen AK79D Max

Youz can use some Rubycon MCZ or MBZ, all are availiable in 10mm, 3300uf 6,3v. But UCC KZG and probably Samxon GD should be aviliable too at those specs.

Thanks for the quick reply.

According to the specs gathered by Oklahoma Wolf the Lelon's have a 10v value, but the caps you listed are 6.3v? I'm still learning, but wouldn't the replacements have to have an identical 10v value?

[Oklahoma Wolf]

Re: AOpen AK79D Max

6.3v should work, as those caps are fed by 5v for the CPU regulator. I just used 10v to be picky

[Operandi]

Re: AOpen AK79D Max

6.3v should work, as those caps are fed by 5v for the CPU regulator. I just used 10v to be picky

That makes sense.

When I start looking for caps is there any reason to go with a 10v cap or something with a higher uf rating, or not to for that matter? Since I'm only going to be replacing the three Lelons I might as well make it worth while and get the best I can find.

[Oklahoma Wolf]

Re: AOpen AK79D Max

Not sure it would be worth the bother. I just replaced the Lelons with the same thing in Panasonic FM. Didn't do a thing for my overclock, but now I don't have to worry about the Lelons puking on me

[Operandi]

Re: AOpen AK79D Max

Ok so browsing Digi-Key (the only source I know of) I was able to find Panasonic NHG, and Nichicon VZ. Both are 6.3v and 10mm rated at 105c; finding 10v caps @ 10mm seems to be problematic. They don't seem to carry Rubycon or Samxon, but I'll keep looking what they do offer.

So, now my questions are the following...

Are those Panasonic, and Nichicon's good choices? Besides Digi-Key are there any other places I should be looking? Are they are any other values I should be paying attention to, ripple maybe? And is 6.3v really OK? even though the original Lelon was a 10v cap (according to Oklahoma Wolf).

[kc8adu]

Re: AOpen AK79D Max

the nhg and vz are general purpose.

[Operandi]

Re: AOpen AK79D Max

the nhg and vz are general purpose.

I see, I'm assuming I need to be looking at low(er) ESR caps?

If that's the case selection at those specs seems to be slim to none, at least that I've been able to find.

[Oklahoma Wolf]

Re: AOpen AK79D Max

If that's the case selection at those specs seems to be slim to none, at least that I've been able to find.

Which is why I used 12.5mm Panasonic FM's

The weird looking fan formation I have them in affects nothing of the board's operation.

[Operandi]

Re: AOpen AK79D Max

1. Rubycon YXG/YXH 2200/6.3.
2. Nichicon VR 3300/6.3 - not low ESR, but can handle ~1A ripple current. Three in parallel makes it 3A, and this is probably on the +5v rail feeding the buck-converter(s) for Vcore, so the amplitude of the ripple voltage is not as critical as the caps sitting on Vcore. It can't be worse than the Lelons, at any rate.

The above was recommended to Oklahoma Wolf for the exact caps I will be replacing. The VR is a general purpose cap and from what I can tell and a step below the Nichicon VZ that I was looking at. So perhaps the VZ/VR series would be alright for this application?

Which is why I used 12.5mm Panasonic FM's

The weird looking fan formation I have them in affects nothing of the board's operation.

I realize that but it's something I'd like to avoid.

I'm being told I should be able to find good caps (Rubycon, Samxon) with the values I need 6.3v (not 10v perhaps), 3300uf in the 10mm size so either I'm being lied to or I simply don't know where to look. Can anyone point me in the right direction as far as sources are concerned?

[Spacedye69]

Re: AOpen AK79D Max

Contact Top Cat, site owner, or fly to Japan?

[yanz]

Re: AOpen AK79D Max

i would say no for nichi vz, it's 105c rated alright but still higher esr. you want 3300uf caps?

choose one of these: 3300uf 6.3v caps 10mmm

[yanz]

Re: AOpen AK79D Max

the 10v 10mm ones are simply not exist. but if you want 12.5mm then there are a bunch of them: 3300uf 12.5mm 10v.

note:
rated ripple current: the higher the better
impedance/esr: the lower the better.

[yanz]

Re: AOpen AK79D Max

2. Nichicon VR 3300/6.3 - not low ESR, but can handle ~1A ripple current. Three in parallel makes it 3A, and this is probably on the +5v rail feeding the buck-converter(s) for Vcore, so the amplitude of the ripple voltage is not as critical as the caps sitting on Vcore. It can't be worse than the Lelons, at any rate.

ok i notice that they are on vrm input, you may have better luck in applying general purpose caps in there. but the ones on vcore (vrm output - caps that closer to cpu) should be the lower esr ones like mbz/mcz, kzg, wg, fm, or (still in evaluation) samxon gc.

2200uF Caps
------------------
6.3v 8mm 10mm
10v 10mm

[Operandi]

Re: AOpen AK79D Max

ok i notice that they are on vrm input, you may have better luck in applying general purpose caps in there. but the ones on vcore (vrm output - caps that closer to cpu) should be the lower esr ones like mbz/mcz, kzg, wg, fm, or (still in evaluation) samxon gc.

2200uF Caps
------------------
6.3v 8mm 10mm
10v 10mm

The output caps are Chemicon KZE, and are fine so I won't be replacing those.

I will contact Topcat, but as a alternate plan a Nichicon, Panasonic, or Chemicon general purpose cap should be alright?

[Operandi]

Re: AOpen AK79D Max

So here is the conclusion...

I had actually received my caps from Topcat and was about to purchase a decent soldering station for the job but couldn't find any of my old boards that I had intended to practice the removal process on.

Faced with the expense of $100+ on station and learning on my own working board I decided it would be best (safest) to just send the boards in to Topcat.

Here are some pictures documenting the results...

The problematic Lelon caps (the top one looks like it was still OK).
[/IMG]


Here is shot of the entire board back from Topcat. The three bad Lelon's replaced with Rubycon MBZ. Although they were fine the United Chemicon KZE were also replaced with a combination of MBZ and MCZ .


Closeup of the Rubycon MBZ where the Lelon's once resided.
[/IMG]


Closeup of MCZ nearest the CPU.
[/IMG]


A shot of the board with the Alpha PAL9045 installed for good measure .
[/IMG]

Its been about a week and the system passed my 12+ hour Prime95/UT2k4 bot match stress test as well as several hours of LAME and Divx encoding.

Though I would have liked to have done the work myself I still learned a lot diagnosing the problem and solution so thanks to everyone that offered their advice .

[Spacedye69]

Re: AOpen AK79D Max

Pretty.

[dood]

Re: AOpen AK79D Max

Why did topcat replace the United Chemicon

[Topcat]

Re: AOpen AK79D Max

^
Because I've seen them fail one too many times, better safe than sorry...

Phil, thanks for your business! Glad they both are working to your satisfaction!