Asus M2N-X recap job

[Gariarto]

Hi guys

I just brought back 2 workstations from one of my customers' offices. I was called in when they were operating unreliably and occasionally throwing blue screens.
The motherboards are Asus M2N-X rev2.01G

After running checks on the OS I was puzzled that nothing seemed wrong with the XP Pro installations. Memory and HD's checked out OK etc. Finally I opened a case to take a peek, expecting to find failed fans or a ton of dust. These units have run 8 hrs a day, 5 days/wk with very very few faults since late '07 so they've done well.
What I DID find was bulged and split capacitors on the VM side of the processor. AHA !!

The 4 showing obvious visible failure are 6.3v 3300uF whilst all others show no visible signs of anything wrong.
Totally stereotypical of a hundred threads and pics in here so I'm only going to ask one question. Its been asked before but I think it was about very low grade stuff.

- Do you think I should replace the whole set or just the visibly bad ?

I know, test them etc but I have neither the time or the ESR meter, so do I blanket replace the lot or do you think I have to ?
Don't think me lazy, I'm just spreading my wings a little with this level of repair. Normally my customer base wants a 2 day turnaround with new hardware and fresh warranties in the box. SO..

The caps list is as follows for the whole board...

They are brown/white and are (United Chemicon ?) printed KZG 105c (7k)

41 capacitors total
7x 16v 100uF
23x 6.3v 820uF
1x 6.3v 470uF
2x 6.3v 1500uF
4x 16v 1000uF (Visibly OK but right by the bad 4)
4x 6.3v 3300uF (the bulged and leaking 4)

My reason for asking is because I'd like to rotate these units back into service this time. Normally the company asks for new gear but these need to stay original if possible because of the software on them. The only 'new' they are getting is the system imaged to new HD's.

Feel free to recommend replacements if you want. I can do the purchasing research alright (I think) but it would be nice to see an experts choice and then do it myself to compare.

Thanks in advance !

[retiredcaps]

Re: Asus M2N-X recap job

They are brown/white and are (United Chemicon ?) printed KZG 105c (7k)

41 capacitors total

Regular members will tell you that United Chemicon makes quality caps except they have a few lemon series. One of those lemons is KZG. They don't like heat and log time members who have done a lot of motherboard recapping and found that they can go bad without bloating.

Since you don't have an ESR meter, the safest thing to do is to treat the non bloated KZGs as "guilty by association". That is, replace them all.

I do understand that if you are under time pressure and don't have a lot of experience soldering, then recapping 41 caps is a daunting challenge.

[severach]

Re: Asus M2N-X recap job

7x 16v 100uF
1x 6.3v 470uF

Have a closer look at the caps for brand and series. UCC does not make a KZG 100uf 16v or KZG 470uf 6.3v. If brown and looking like KZG then they are probably UCC KZE which you shouldn't replace because nothing you can buy substantially exceeds KZE. Identifying a few good series could greatly reduce your work.

How many you replace depends on the cost of failure, the cost of doing extra work, the cost of downtime waiting for parts, and the likelyhood that the board will be damaged by the repairs. You can minimize repair time by doing as few of the following as desired:

1) Replace all bulged and failed caps. If identical caps are failing in both stressed and non stressed areas then the formula is probably faulty and all should be replaced.

2) Replace known bad caps right after regulators and in hot areas. Capacitors such as the 4x 16v 1000uF are before the regulator and not heavily stressed unless continuously hot. Note that some caps may be hot only when extras are plugged in, such as capacitors under video cards.

3) Replace all known bad caps.

4) For very old products or well funded projects you might want to replace all caps as caps have a limited lifetime no matter how good they once were.

The more you do the more reliable the repair will be.

How hot is too hot depends on how good the cap is. Many el-cheapo caps fail even if constantly cold. KZG and other weak formulas should be replaced if they run luke warm. Panasonic last per spec in areas too hot to touch.

[Gariarto]

Re: Asus M2N-X recap job

Man you guys are fast ! Thankyou both for your input.

You've both echoed my thoughts just to replace all of them on two counts. Age and known poor series. OK, sigh.. I guess I just wanted to hear it from the best. My next stop is Digikey or similar.

Severach - "Have a closer look at the caps for brand and series. UCC does not make a KZG 100uf 16v or KZG 470uf 6.3v. If brown and looking like KZG then they are probably UCC KZE"

I did take another look at the 2 ratings you mentioned and I was wrong on the smaller. They are KMG, that text is very small ! The 470uf 6.3v is definitely printed KZG though.. All the caps are the same color scheme throughout so I guess after seeing enough KZG I assumed wrongly about the rest. Sorry.

My soldering skills are reasonable, I usually get fairly close to a factory-ish finish without toasting the component or damaging the traces, but on larger things than the smaller of these caps. The only thing I see as my potential time killer is clearing out the holes on the smallest when solder runs inside as you remove the lead. Hate that fiddling with heated picks and needles etc.

I blame you guys for all this !! It all started with a 2 secs to black monitor I fixed under this forums' guidance, and now look !!! Well, actually, I'm enjoying this, somewhat.. Haha !!

Thanks again boys.

[retiredcaps]

Re: Asus M2N-X recap job

They are KMG, that text is very small !

KMG are good.

[Exacta]

Re: Asus M2N-X recap job

I was just sent here from the folks at bleepingcomputer.com and the first thing I see is this thread title. I've got a m2n61-ar and am getting "random and frequent" system freezes (just like your description) on my HP s3700y. Even when the onboard graphics is disabled in BIOS and I use a low end PCI-e graphics card with a fan, I still get the system freezing. When using the graphics card the heat sink for the onboard gets blistering hot. Although I cannot detect any leakage or bulging is it possible that the excessive heat could make the/a capacitor(s) fail? As you can tell I'm a first class novice when it comes to motherboard electronics to the highest degree. I'm just trying to better understand why the system would completely lockup when I'm using the PCI-e instead of the onboard graphics.

Thanks for any info.

[dmill89]

Re: Asus M2N-X recap job

I was just sent here from the folks at bleepingcomputer.com and the first thing I see is this thread title. I've got a m2n61-ar and am getting "random and frequent" system freezes (just like your description) on my HP s3700y. Even when the onboard graphics is disabled in BIOS and I use a low end PCI-e graphics card with a fan, I still get the system freezing. When using the graphics card the heat sink for the onboard gets blistering hot. Although I cannot detect any leakage or bulging is it possible that the excessive heat could make the/a capacitor(s) fail? As you can tell I'm a first class novice when it comes to motherboard electronics to the highest degree. I'm just trying to better understand why the system would completely lockup when I'm using the PCI-e instead of the onboard graphics.

Thanks for any info.

Yes heat is one of the major causes for capacitor failure. It is also common for UCC KZGs to fail without showing any physical signs (bloating/leaking). That being said you may have a larger problem than bad caps. Your motherboard has an nVidia nForce 430 chipset. nForce chipsets are known to run hot (as you have noticed) and crack the lead free solder in the BGA (ball grid array) that attaches them to the board. Unfortunately there is a good chance that a failing/detaching chipset could be the cause of your issues. A reflow may fix this temporarily but the only permanent fix would be a new motherboard with a different (non-nVidia) chipset.

[Exacta]

Re: Asus M2N-X recap job

Yes heat is one of the major causes for capacitor failure. It is also common for UCC KZGs to fail without showing any physical signs (bloating/leaking). That being said you may have a larger problem than bad caps. Your motherboard has an nVidia nForce 430 chipset. nForce chipsets are known to run hot (as you have noticed) and crack the lead free solder in the BGA (ball grid array) that attaches them to the board. Unfortunately there is a good chance that a failing/detaching chipset could be the cause of your issues. A reflow may fix this temporarily but the only permanent fix would be a new motherboard with a different (non-nVidia) chipset.

Great info....thanks. A NEW Mini-ITX board with an AM2 socket are a near impossibility to find. I fear that the many used boards available would be chasing good money after bad.

Thanks for the quick response.

[Gariarto]

Re: Asus M2N-X recap job

dmill89 is right about that nVidia chipset, they get very hot !

A large number of the boards I used with those chipsets, I swapped out the little heatsinks with larger, fan assisted 'sinks. I would use old stock leftovers originally for the early AMD Thunderbird series CPU's. Later, where case design allowed I put in front and rear 120mm fans for a good cooling flow-through. On the chipsets I'd still use larger heatsinks but without extra whiny little fans.
Or, if you do plan to scrap the board your re-purchase options are limited as you know. If you can't get old stock of the same (which I wouldn't if I didn't have to). I'd get this board, I've used it a few times and had no problems as yet. Yet. ASRock A785GM-LE AM3/AM2+/AM2. Still available at such as Newegg for $50 or so. If you do get to a point of wanting to do a full re-cap, consider you'll get near the purchase price of the Asrock with capacitors, shipping and time. Plus your heat problems are erased.

Personally I would be looking into a lot more first that would manifest actual or apparent system 'freezes'. There's more fundamental stuff to rule out first.

Is bad or rogue software grabbing 100% of the processor time ? - Watch the processor usage in Task Manager
What does Event Manager show ?
Does your Hard drive have weak/bad sectors and Windows is trying to read and re-read the damaged ones ?

On a diagnostic path.. If you can, throw in a spare known good HD and do a clean install of say, XP. Does it produce errors during installation ? Doing this answers a few questions at once, like ruling out software causes. Does it run stable from such as Hirens Boot CD running Mini Windows XP ? There are a few things that can seem to be your system 'freezing'. First one I'd look at is bad sectors on your current HD. Windows will seem to hang while trying to read and re-read weak or damaged sectors. Run Memtest 86 from DOS to check your RAM. Again, Hirens will have all those tools on the CD.

Try some steps to eliminate and identify. Hows your PSU ?

G.

[Exacta]

Re: Asus M2N-X recap job

@gariarto - Very good response and I appreciate the info. As I said in my original post that I would start other threads to address other issues with the problem. I would like to state, however, that I checked the mobo you posted and first of all it would fit and the insertion dimensions are the same. I'd never run across this as my searches have always bee mini-ITX vs. mini-ATA. So thank you!! The new thread that addresses your points can be found here: http://tinyurl.com/cbcklmn

[Gariarto]

Re: Asus M2N-X recap job

To close this thread I succesfully, completely re-capped these motherboards using Panasonic FM and FC series capacitors. Both tested and run stably without issue. Thanks for all your help !

[mockingbird]

Re: Asus M2N-X recap job

FM and FC are not adequate replacements for KZG, especially not in a VRM application such as this.

They're not rated to handle the ripple and they don't have a low enough ESR. They are no doubt overheating and should bloat in no time.

Next time use Nichicon HM/HN/HZ series. I would personally not bother with M2N because of the faulty northbridge chipset.

[c_hegge]

Re: Asus M2N-X recap job

^
Agreed. Don't ever use FM or FC (especially the latter) to replace a KZG.

[Gariarto]

Re: Asus M2N-X recap job

OK, well, they're back onsite now so I guess I'll just have to wait and see.
I can monitor their progress every couple of months.

[Leeroy89]

Re: Asus M2N-X recap job

hi sorry to add to this old thread, i have the same bad caps int the M2N.
the KZG 16v 1000uf, tk 6.3v 820uf, 2 with a slight bulge. i looking for advice of some current replacement ones please
thank you in advance
Lee

[Leeroy89]

Re: Asus M2N-X recap job

^
Agreed. Don't ever use FM or FC (especially the latter) to replace a KZG.

what would you use please im in uk

[SMDFlea]

Re: Asus M2N-X recap job

what would you use please im in uk

He hasn`t posted anything since 2015 so you might be in for a long wait. Hopefully someone else will reply and help

.

[Leeroy89]

Re: Asus M2N-X recap job

do you have any idea please

[Leeroy89]

Re: Asus M2N-X recap job

Do you have any idea please

[momaka]

Re: Asus M2N-X recap job

Panasonic FM, FR, or FS will be OK for KZG, though not ideal, particularly for caps around the CPU... but for those, you can use polymers.

That said, here are some possible options for KZG that are not exactly equivalent, but good enough for other areas on the motherboard:
Rubycon ZLH, ZLK, ZL, ZLJ, ZLQ
Panasonic FM, FR, FS
Nichicon HV, HW
United Chemicon KZH, KZM, KZN

Since I have a few variants of the M2N variety (namely M2N68-LA and similar boards for OEM PCs), I'd venture and say that even much "lesser" caps will work is certain areas of the board. For example, any caps close to USB headers are typically for filtering 5V going to the USB ports (ASUS typically uses TK ATWY or KZG 6.3V 820 uF here.) Same with most caps between the PCI and PCI-E slots. These spots don't need low ESR caps, so even GP 105C caps will work. Even many of the 820 uF caps close to the back I/O ports or the SB itself are filtering either PSU rails directly or after a linear regulator... so low ESR/impedance is not too important.

You can go as "bad" (in terms of low ESR/impedance specs) as Panasonic FC, Nichicon HE or HD, Panasonic FC or FK, and UCC KY or KYB or KZE.