recapped ASUS A8N-LA, working intermittently.

[Mad_Professor]

I just got done recapping all the KZG caps on an A8N-LA board.
This board was dead when I got it, it would automatically turn on and do nothing after troubleshooting memory and power. The only thing that made me recap it was the three blown KZG.

There were 12x 820, 2x 1800, 1x 470 all kzg and at 6.3v. I replaced 2 with 1800uf 6.3 HN, one with 470uf 6.3 HN and the rest rubycon MCZ 820uf. I bought the caps from badcaps.net.

After the recap, it still did the same thing like it was shorted somewhere. I bumped my hand into one of the Panasonic FJ 1500uF 6.3v near the heatsink. At that moment I wasn't paying attention and was trying to troubleshoot the system. I decided to try again and the system did post but far from stable. I ask myself what changed, then I remember what I did.

What I have noticed is that 5 of panasonic FJ are loose like the leads are loose in the bungs. Four of these are near where a group of blown KZG, one between the heatsink and memory, This one is really loose.

Am I correct to assume that these FJ have failed or are going bad or is it something else?

There's also acouple of small Panasonic 100uf 16v scatter across the board, could these be causing problems too?

What could be causing the board to work intermittently?

I really need an ESR and capacitance meter.

[PCBONEZ]

Re: recapped ASUS A8N-LA, working intermittently.

""What could be causing the board to work intermittently?""
The KZG you didn't replace for one...
You need to replace -ALL- the KZG.
#1: Not all bad caps bloat.
#2: KZG are ~famous~ for going bad without bloating.

The loose caps sound like handling damage and it's probably a good idea to replace them.
- But note: Sometimes they mount caps a tad high. If so, they will rock side-side but in one direction only. Lead to lead they won't rock. 90 degrees from that they will. If that's what is going on it doesn't hurt anything and you can leave them alone. ... But, stop bending them back n forth once you know that's what's up. You might work harden and snap a lead. - The stripe on the side will indicate which way the leads are.

If the small Panasonic are are 105C they should be fine.
.

[Mad_Professor]

Re: recapped ASUS A8N-LA, working intermittently.

""What could be causing the board to work intermittently?""
The KZG you didn't replace for one...
You need to replace -ALL- the KZG.
#1: Not all bad caps bloat.
#2: KZG are ~famous~ for going bad without bloating.

I did. That's the problem I replace them with nichicon and rubycon it was about 15 caps total and 2 hours of work.

[mockingbird]

Re: recapped ASUS A8N-LA, working intermittently.

1) It could be the power supply
2) Not to offend you, but it could be the work. Post pics of your solder joints so we can judge if your work is competent.

[Mad_Professor]

Re: recapped ASUS A8N-LA, working intermittently.

1) It could be the power supply
2) Not to offend you, but it could be the work. Post pics of your solder joints so we can judge if your work is competent.

1: It plugged into a new but known to work PSU, it's Thermaltake 450W I just got it acouple of weeks ago and have been using it.

2:... down below.

I managed to get it to post and boot into memtest and it did one pass fine. But when it resets it hangs, or if I do ctrl-alt-del it hangs too. It's acting like I have bad caps or something.

[mockingbird]

Re: recapped ASUS A8N-LA, working intermittently.

Thermaltake is making me frown a little bit but it would be wise to replace ALL the capacitors at this point. What have you got to lose. Badcaps has all the 8mm ones I think. Check the Samxon stock.

Your soldering is good BTW.

[PCBONEZ]

Re: recapped ASUS A8N-LA, working intermittently.

If photos are from after the work you still have KZG scattered about.

If you are using 4 sticks of RAM then try it with two.
Less load on RAM VR and MCH.

Also some Asus are bitchy about what RAM you use.
Might try another brand and double verify the specs on what you are using.
.

[Mad_Professor]

Re: recapped ASUS A8N-LA, working intermittently.

Thermaltake is making me frown a little bit but it would be wise to replace ALL the capacitors at this point. What have you got to lose. Badcaps has all the 8mm ones I think. Check the Samxon stock.

Your soldering is good BTW.

What's the matter with thermaltake? I got it for $34, I'm only using it for bench testing.

That's what I was thinking. I can't seem to find any datasheets for FJ series, I see alot of dead links to what use to be datasheets.

Thanks, I've been practicing.

If photos are from after the work you still have KZG scattered about.

If you are using 4 sticks of RAM then try it with two.
Less load on RAM VR and MCH.

Also some Asus are bitchy about what RAM you use.
Might try another brand and double verify the specs on what you are using.
.

Nope, I only took them before I began work, just as a precaution incase I didn't finish and had to run.

I'm very familiar with asus boards.
I was only using one stick, it was either a corsair, some no name, and kingston ram, all DDR PC3200 2.5v I was using to test.

Could it just be that these FJ were overloaded from the failing KZG and are just bad? Because they are all 6.3v, and the board does run stable if I can get it to post.

[PCBONEZ]

Re: recapped ASUS A8N-LA, working intermittently.

Could it just be that these FJ were overloaded from the failing KZG and are just bad? Because they are all 6.3v, and the board does run stable if I can get it to post.

That could be. Not saying likely, but it could be.
If the FJ and KZG were in parallel there is probably a good chance of that.

Also check that Thermaltake for bad caps.
The Asus might be more sensitive to bad PSU caps than whatever it was used/tested on before.

...
Currently it's hard to start but once it does it runs fine?

.

[mockingbird]

Re: recapped ASUS A8N-LA, working intermittently.

That's what I was thinking. I can't seem to find any datasheets for FJ series, I see alot of dead links to what use to be datasheets.

Here you go:

[xxx][xxx] = ESR(or ESR range) at [8x20mm][10x20mm]
HZ, GA -- [.009][.007]
------------------------------------------------------
KZJ, GC, HN, MCZ -- [.012][.010-.011]
------------------------------------------------------
FJ, FL, WGL2, NRSJ -- [.016][.013]
MBZ, HM, WG, GD, KZG, NRSK -- [.018-.019][.013]
KZG, ZLG -- [.020-.021][.013-.014]

[PCBONEZ]

Re: recapped ASUS A8N-LA, working intermittently.

Panasonic FJ and FL are only sold direct to manufactures so you won't find a data sheet online.
The ones you do see for sale are over-stocks or someone in the manufactures organization has a little side business going on.

Willa tripped over the engineering doc for FJ a few years ago and linked to it.
It has the specs in it but the PDF is 24 pages long.

Used to exceed the max PDF upload size here but it seems that's been increased.
So here it is:
Go to page 12...
.

[Mad_Professor]

Re: recapped ASUS A8N-LA, working intermittently.

That could be. Not saying likely, but it could be.
If the FJ and KZG were in parallel there is probably a good chance of that.

Also check that Thermaltake for bad caps.
The Asus might be more sensitive to bad PSU caps than whatever it was used/tested on before.

...
Currently it's hard to start but once it does it runs fine?

.

I look in the fan vent of the Thermaltake, looks like crappy quality caps, brands I've never heard of before. I tried an old 20 Pin ATX PSU and it does the same thing with that. Short of going out and buying a quality PSU like corsair, seasonic or enermax, I don't know what a good PSU is anymore. Seeing the insides of acouple made me realize they typically use the same quality of capacitors.

It loads Ubuntu 10.04 32bit and Linux Mint 11.04 64bit via pxe and it runs fine. I'm currently letting it idle with mint. I managed to get it to boot with 2 sticks of 256MB DDR 3200 and EVGA Geforce 220 PCI-E card.

EDIT: It just hang, so it loads an O/S it just doesn't run stable. it's almost like I was overclocking and not providing enough voltage to either memory or processor.

It's like that lawn mower that takes 20 tries before it will actually turn over.

The only problem is I can short the reset pins and the machine will reset but if I restart via an O/S it will go down normal and "reset" but it will hang and not come back up.

Here you go:
Originally Posted by PCBONEZ View Post
[xxx][xxx] = ESR(or ESR range) at [8x20mm][10x20mm]
HZ, GA -- [.009][.007]
------------------------------------------------------
KZJ, GC, HN, MCZ -- [.012][.010-.011]
------------------------------------------------------
FJ, FL, WGL2, NRSJ -- [.016][.013]
MBZ, HM, WG, GD, KZG, NRSK -- [.018-.019][.013]
KZG, ZLG -- [.020-.021][.013-.014]

I assume that's the esr values? what about ripple, I read somewhere on here they have matching values to rubies MBZ caps?

Is this correct?

[PCBONEZ]

Re: recapped ASUS A8N-LA, working intermittently.

Check for bad MOSFETs over by the RAM.
May just have "Asus Syndrome".

.

As it says.
[xxx][xxx] = ESR(or ESR range) at [8x20mm][10x20mm]
-
That chart was just to show which 'grades' the various common series are.
Since 'what is better than what' is the same by ESR or Ripple there was no point in showing both.
- The quote only shows the top 3 grades.
The complete chart is way longer than that.
If you want to add all the ripple values go right ahead.

The 8mm FJ have slightly better specs than 8mm MBZ.
- That's why FJ is shown over MBZ.
The 10mm are either an exact match or nearly so.

FJ and MBZ are too close to consider different grades.

The grades are divided by the
------------------------------------------------------
line in the chart.

It would be more clear if you saw the whole conversation where I posted that.
.

[Mad_Professor]

Re: recapped ASUS A8N-LA, working intermittently.

Well scratch what I said earlier about the system loading an O/S and not running stable. I guess Linux Mint 64bit didn't like something and keeps hanging, but ubuntu and linux mint 32bit on other hand runs fine. Even running a flash intensive application like youtube it ran fine.

So I guess this board is just hard to start.

How would I check for bad FETs? would I have to remove them from the board to check?

Also Would nichicon HM make decent replacements for the FJ
HM: 1500uf 6.3v, 1.95a ripple, 0.16 ESR

Right now I have 4 sticks of ram running, 2x 256 and 2x 512 running along with evga GF 220, and the system is running, as long I don't disconnect the PSU from supply. When I do, the board becomes hard to start. Once I get it going, it's fine. If I shut it down but don't unplug the PSU from supply, I can make any hardware changes without issue and be able to power up with no problem.

It's weird.

[mockingbird]

Re: recapped ASUS A8N-LA, working intermittently.

I would go HN instead. HM will probably work.

[PCBONEZ]

Re: recapped ASUS A8N-LA, working intermittently.

as long I don't disconnect the PSU from supply. When I do, the board becomes hard to start. Once I get it going, it's fine. If I shut it down but don't unplug the PSU from supply, I can make any hardware changes without issue and be able to power up with no problem.
It's weird.

Shut it down.
Disconnect the PSU. [Encourage the problem.]
Without starting the system.. reconnect everything.
Without starting.. check the voltage on +5vsb.
.

[Mad_Professor]

Re: recapped ASUS A8N-LA, working intermittently.

what ever is making this board work intermittently before, it's dead now.
I can't get it to post, I've been trying since last night. I switch on the PSU and the board comes on automatically, meaning it's dead or there's a short somewhere, It's not even in a case.

[PCBONEZ]

Re: recapped ASUS A8N-LA, working intermittently.

I think your PSU has +5vsb issues.
Or an issue on the board is killing +5vsb.
.
Either that or it's ASDS: "Asus Sudden Death Syndrome".
[An Asus dying for identifiable reason isn't all that unusual.]
.

[Mad_Professor]

Re: recapped ASUS A8N-LA, working intermittently.

Sorry I haven't been able to reply. Opendns is having trouble resolving the badcaps.net domain, I switch to google dns and now I'm able to reach the site.

Anyways I haven't bother much with the board since I got other projects cooking. But I did try my enermax PSU out of my computer and it does the same thing so.

I might try recapping once more but if it doesn't fix it, salvage and scrap it.

[PCBONEZ]

Re: recapped ASUS A8N-LA, working intermittently.

See if you have a shorted [or partially shorted] cap on +5vsb some where on the mobo.
Might be a small one.
.