Nova capacitors???

[starfury1]

Re: Nova capacitors???

yeah on the BIOS it seemed like a logical step someone not aware of Badcaps would take so I was sort of hoping a re-flash might get you back to the stage of booting but freezing...seems not

I just have a feeling it might be more then caps but as I said I don't know much on the MB.

this is really a just in case and by the sounds of it you dont need it but I'll post it anyway (you may not have found it yet)

its pretty much basically how to check VRM, I am sure you probably beyond it technically Testing VRM by Akor

its really trouble shooting 101 I suppose but some people need it.


I know chip sets have been known to die, issues with BGA soldering. maybe something with Power Good sig (cant recall fully how that works but there a few posts on it round here)

I guess till you replace the caps we wont know if that is whats keeping it out of action....I am with you thought on not using expensive stuff at this point.
(I dont think we have a confirmation on this being a cap symptom for this MB)

I have been somewhat busy so really haven't had a chance to do some googling on it

I don't get enough exposure to PSU's and MB's to gain a lot of experience these days, so I cant offer anything overly useful on this...still got training wheels with it really in some respects

Anyway I think you on the right track, to not overly expect caps to fix the issue
so suitable cheapie is warranted

-----------------------------------------------------------------------
I just had a look at the MB photos again and hope you don't mind the repost of one here for reference to what I am about to say;

For those that know, Is that a single Phase VRM?
(I suspect it is, 2 fets 1 green coil)
Is it likely to be 5 Volt VRM
(I suspect if they are all 6V3 caps of 1500uf)

Now bearing in mind I am only working from the photo and have never seen this MB in the flesh
So its pure "Guess work" and I could TOTALLY have it WRONG!


The BLUE X I suspect is VRM input (2 Caps)
THE RED XI suspect is VRM output (5 Caps)

Here comes the bit I and querying and suspecting of possibly generating this fault symptom

If you look at the far two caps they appear to be beside a regulator (whatever... switcher, mosfet) near the chipset

THE PINK Magenta type colour

is it possible this not functioning is responsible for the "no boot" situation
What are the chances of the Chipset being damaged from this.

I would do point to point continuity checking and see where those to caps connect to
They may well be part of the VRM output and have nothing to do with that circuit which appears it might power the chip set in some way.

Its seems like a good theory but does it hold any water?

like I said, No Expert on any of this and its purely my suspicions from the photo and symptoms as described



Looking at it further and knowing MBs and positions does not mean that thats the "function" of the caps...other possibilities could be read into that arrangement The yellow coil is posing questions in my mind of being related to VRM input, maybe 2 next to it are VRM input the blue are GP filtering for MB and 3 red plus 2 pink are VRM output

may suspicion is 1 or 2 of these caps are suppling dirty power to the chipset regulator (I think it probably has one?) which is then causing it to not operate.

Anyway thats my not so educated guess and I could totally be barking up the wrong tree
--------------------------------------------------------------------

Just wondering do you have an ESR meter and Capacitance meter?
useful item to have for MB psu repair


Cheers

[Agent24]

Re: Nova capacitors???

Well I've been looking around and I think I've finally found where the Nova capacitors may come from:

"Fenghua Advanced Technology" (www.fenghua-advanced.com)

here's a datasheet I picked at random:

That cap look familiar?

They also have distribution in NZ by "arrow components" http://www.fenghua-advanced.com/english/server_02.asp - so it looks like this really could be it.

Pity that website is horrible

Still, I did find this http://www.fenghua.com/eng/index_eng.html which has more and seems better datasheets (although I am not sure if the sites are from the same company)

I just have a feeling it might be more then caps but as I said I don't know much on the MB.

its pretty much basically how to check VRM, I am sure you probably beyond it technically Testing VRM by Akor

Thanks for that, as I said, I'm better with computers than the electronics themselves, unforunately....

That how-to seems fine but I have a question, when talking about VRM: eg:

Measure resistance from power supply pin (+3.3, +5, +12, -5, -12) to input of VRM.

I take it we're talking about the MOSFET itself, right?

In which case I'm still confused as to which pin I would be checking against etc. (sorry, never really did much on these)

The Fets themselves are AP60N03S Datasheet here

Now, this might answer some of your questions about the circuit.

The board has 4 of these 60N03S (actually, both boards have 4 each) but on the photo below 2 of them are near the socket, 2 are near(er) the northbridge

All the bigger caps are 6.3v, 1500uf, and all are bulging.

-----------------------------------------------------------------------
I just had a look at the MB photos again and hope you don't mind the repost of one here for reference to what I am about to say;

For those that know, Is that a single Phase VRM?
(I suspect it is, 2 fets 1 green coil)
Is it likely to be 5 Volt VRM
(I suspect if they are all 6V3 caps of 1500uf)

Now bearing in mind I am only working from the photo and have never seen this MB in the flesh
So its pure "Guess work" and I could TOTALLY have it WRONG!


The BLUE X I suspect is VRM input (2 Caps)
THE RED XI suspect is VRM output (5 Caps)

Here comes the bit I and querying and suspecting of possibly generating this fault symptom

If you look at the far two caps they appear to be beside a regulator (whatever... switcher, mosfet) near the chipset

THE PINK Magenta type colour

is it possible this not functioning is responsible for the "no boot" situation
What are the chances of the Chipset being damaged from this.

I would do point to point continuity checking and see where those to caps connect to
They may well be part of the VRM output and have nothing to do with that circuit which appears it might power the chip set in some way.

Its seems like a good theory but does it hold any water?

like I said, No Expert on any of this and its purely my suspicions from the photo and symptoms as described



Looking at it further and knowing MBs and positions does not mean that thats the "function" of the caps...other possibilities could be read into that arrangement The yellow coil is posing questions in my mind of being related to VRM input, maybe 2 next to it are VRM input the blue are GP filtering for MB and 3 red plus 2 pink are VRM output

may suspicion is 1 or 2 of these caps are suppling dirty power to the chipset regulator (I think it probably has one?) which is then causing it to not operate.

Anyway thats my not so educated guess and I could totally be barking up the wrong tree
--------------------------------------------------------------------

Dirty power from the bad caps or perhaps if something went quietly open circuit...

I assume nothing is shorted or else we'd have problems like this: https://www.badcaps.net/forum/showthread.php?t=211

Just wondering do you have an ESR meter and Capacitance meter?
useful item to have for MB psu repair
Cheers

Unfortunately I have neither...

[Krankshaft]

Re: Nova capacitors???

If you want to check the FETs for shorts set your meter to the diode check function.

Then measure from source to drain you should only get a reading in one direction. If you read a short the FET is gone.

[PCBONEZ]

Re: Nova capacitors???

There is usually a single coil between PSU plug and VRM input caps.
Other coils, one per phase, in VRMs.

.

[Agent24]

Re: Nova capacitors???

If you want to check the FETs for shorts set your meter to the diode check function.

Then measure from source to drain you should only get a reading in one direction. If you read a short the FET is gone.

I assume at least either pin would need to be disconnected from the circuit before doing this?

[PCBONEZ]

Re: Nova capacitors???

>> If you read a short the FET is gone. <<

If it's shorted lifted pin won't matter.

[Agent24]

Re: Nova capacitors???

I just called Sicom after they didn't return the email I sent last week, but they confirmed what I suspected - the caps are branded LH.Nova, and the only sensible google result for that turns up on fenghua-advanced.com

They also told me that XPB was not a series as such, but just the lead-free version of that cap.

From what I gather they're just some cheap brand but they should be good enough for testing so once I confirm the mosfets aren't dead I guess I'll order some and see what happens

[Agent24]

Re: Nova capacitors???

>> If you read a short the FET is gone. <<

If it's shorted lifted pin won't matter.

Ok, did a test on all 8 fets across both boards in both directions using diode test across drain/source.

the reading would start low and get high, sometimes fast sometimes slow. stop or slow down a lot at around 400-700 but keep going up (the caps charging?)

reverse the probes, it would go down to or around 0 then back up again

Nothing stayed constantly on or around 0 so I assume this means nothing shorted?

[starfury1]

Re: Nova capacitors???

Some of what I posted above wasn't to well presentsed and was more a first instance thought

On the Fets
I don't thinks the fets are the problem but it doesn't hurt to check them....normally as bonze said they will go short (like a piece wire, 0 ohms...or near something like that)
(they are not called "fire transistors" for nothing)

What I was trying to figure out was what would be most likely to cause that symptom

I thought maybe chip set or chip set pwr supply

bonez

There is usually a single coil between PSU plug and VRM input caps.
Other coils, one per phase, in VRMs.

I suspect the Yellow coil is that one.

Another thing that may help you is to get the PDF for the VRM controller chip.
It will give you an idea of how the circuits put together there are posts of pdfs linked I have put up in other threads.

probably a lager chip 20 pin or so ...
(might be the one near the power connector...I don't know)

VRM doc
I think the doc really is more point to point (continuity) testing and checking DC rails.

VRM can be powered from either 12 Volt or 5 Volt
older will probably be 5V newer stuff 12V

Your case I suspect 5 Volt from age and the fact it has 6V3 caps.

so very basically you have a "few caps for input" a "controller chip" and then the "output caps" that feed the CPU

The idea is its a "Voltage Regulator"
That keeps very "tight voltage control" under "huge current demands" in a very "short orders of time".


here is a link to pdf on the HIP6301 as an example Here

There ia better PDF that gives lot more detail on a VRM circuit ( with an older chip), its more of a how they work when designing
(I think the link is dead in the above thread)

the above should give you a better idea of basically what going on with it.


Some may not agree with what I've posted below, so its a case of make up your own mind based on mine and others opinions
(and yes I could be wrong)


IF what I suspect is the case and the chipset is in no way damaged them by rights new caps should sort it.
(here hoping anyway)


Not sure if I did say it or not now but General Purpose caps may get the VRM up and running but they will die fairly quickly as the caps arn't up to it

Ideally you should never use used caps, but if they tested OK they would do for a test I think. (why I asked what you had test Eq wise)


On capacitance
you can get away with going up 1 maybe 2 steps or possible down for a test
So if you had 9 GF samxons 1000uf to hand you could probably get away with them for a test

But Ideally same with same or go a bit higher 1800 uF or 2200uf (max)

just remember change spec parts will change operation a little and its a matter of knowing how far or if it will be detrimental to circuit operation.

going down will probably work, but at possibly slightly worse specs and shorter life

you see in a lot of cases
3300uf used instead of 1500 or 2200 uF but half as many ...get the idea
(this is why you find when 3300uF is used that there are empty spaces on the older MB's PCB)

It dos depend on the circuit etc
so best to stay close to original parts ...
(a tad above wont hurt I think thought)

I modded the last Gigabyte to 2200uf (9) from 3300uf (4) Here

there is a little latitude here, mostly.... but just don't push it too far.

HTH Cheers

[Agent24]

Re: Nova capacitors???

The guy from Sicom said the caps are used a lot in motherboards (though that means nothing - look at the crap caps that were already in there!)

They seem to me to be an el-cheapo brand but like you say should get it at least running if the caps are the problem

So I think I'll just grab a few of the LH.Nova caps and see what happens, seems easiest at least

[starfury1]

Re: Nova capacitors???

well yeah like I said mostly they will work just don't leave them there as a repair
and expect it to operate for a long time or at best specs if they are not low ESR types

depending, but chances are those GSC's probably seen a year or 2 action

So go for it mate

if the LH are a Low ESR type you will probably get a quite a few months out of them for sure...if not more...just don't expect 5 years...

You know what to look for now so check them or run them till you start getting flaky behavior (me personally would rather pull them before flaky things start happening)
Also bear in mind this type of symptoms can becaused by PSU...freezing and reboots

just hope the other issue is down to caps

keep us posted on how you go

Cheers

[Agent24]

Re: Nova capacitors???

LH I believe is just part of the brand name: "LH.Nova"

From a japanese website on capacitors: http://babelfish.altavista.com/babel...no.html#lhnova

(unfortunately, a bad translation by babelfish is really all you can get)

They also have a little comic, I can't read Japanese but I think the joke is about the fake rulycon capacitors..

http://capacitor.web.fc2.com/image3/...omake_001.html

original website is http://www.capacitor.web.fc2.com

I'll certainly keep you all posted on what happens with these boards, as soon as I get the new caps and have enough time to do the recap

[Agent24]

Re: Nova capacitors???

So, I finally got the capacitors (yes I know it's been a month!)

Anyway, I've attached a photo and the spec sheet for the LE series (which is what appears these caps are)

I guess we'll see what happens with them, which should be this weekend

[Newbie2]

Re: Nova capacitors???

I've seen LH.NOVA caps in a few things, mainly in the tiny power supplies of cheap $20-$40 DVD players. They look like any other cheap Taiwanese cap, but for your purpose if they revive your motherboards they should work fine for a good amount of time (1 year at least) if the system they are in runs well-ventilated.

[Agent24]

Re: Nova capacitors???

Well, I replaced the 1500 and 1000 caps on the Intel board today, unfortunately it's still not working.

I'll try looking at the BIOS chip at some point (when I have a PLCC extractor!)


Probably try my luck with the other board tomorrow... maybe it will be more successful ...

[Agent24]

Re: Nova capacitors???

Well, I'm glad I did the other board because, surprise surprise, it works!





currently running a celeron but I'm going to put a P3 1.13ghz Tualatin in it (works fine in there, but the heatsink I'm using is junk for a P3 so I don't want to overheat it or anything)

I'll pop some more photos on here later...

[Newbie2]

Re: Nova capacitors???

Well, I'm glad I did the other board because, surprise surprise, it works!





currently running a celeron but I'm going to put a P3 1.13ghz Tualatin in it (works fine in there, but the heatsink I'm using is junk for a P3 so I don't want to overheat it or anything)

I'll pop some more photos on here later...

Great job there Agent24!

You can keep the NOVA capacitors in it (if you used them) since they are low ESR caps and will last you at least 1 year of normal use. You can swap them out for Japanese (Rubycon, Nichicon, Panasonic, Sanyo and United Chemicon are recommended brands) capacitors.

[starfury1]

Re: Nova capacitors???

good stuff mate
pity about the other MB but it still may be salvageable if you can nail why it failed

yeah I just keep an eye on the caps if you are going to keep it, you should get a year or more if they are half decent
even the crap half baked GSC see a year or 2

just if you are intending on recapping try and get some decent caps so you know it will last for a few years...although this stuff is no getting long in the tooth.
but there are some apps its well suited for regardless of the age of the stuff.

if you do have a further bash at the other keep use posted on what you find mate

cheers

[Agent24]

Re: Nova capacitors???

Yeah, now that I know it works I'm thinking of putting Rubycon or something in it instead - although I'm also tempted to wait and see how long the Nova ones last too, but that might be asking for trouble...

For the other board I have my suspicions about the BIOS being corrupt or something, but I can't do anything about that at the moment as it's PLCC and I don't have the right equipment.

The board that is working, I already reprogrammed the BIOS chip, but it didn't work with the bad caps so maybe it was both. Who knows?

[linuxguru]

Re: Nova capacitors???

Nova is marginal - I've seen them on the primary side of Powmax/Leadman or similar ATX PSUs, and I've seen a few bulged ones. Almost any Panasonic will be better, even 85c M series.