Motherboard damage

I'm hoping someone would be knowledgeable enough to help me here.
Motherboard is Asus P5LD2 Deluxe and I have two sticks of OCZ2P10001GEE
which I had been running dual channel at 3-4-3-11 and around 950 FSB.

I was having some random crashes over the past couple of days. Looked
inside and turns out the waterblock on the Northbridge had popped off, with
the clamp ripping out one of the looped fasteners on the motherboard it was
attached to. Put the waterblock back but still no dice. After using
memtest, it turns out that the second DDR memory channel (pair of slots) is
gone--the same RAM module would work in the A slots one but not the B
slots--errors in the second, with error rate seeming to be somewhat
proportional to the FSB frequency I set in the BIOS.

Looked under the waterblock again and it looks like there's a missing
surface mount ceramic capacitor. I think I may have crushed it while
reinstalling the waterblock. So either from overheating or breaking the
cap, some damage appears to have occurred and now I can only use one of my
1 GB sticks D: It's sure strange though that the second channel slots work
at all; I wouldn't have expected a partial failure with error rates
depending on the FSB...

My question is, can I just replace the cap I think I crushed with a random
one, or maybe unsolder one of the others around it and measure its
capacitance with my LCR meter and use that, in the hope of restoring
function? Or what if I didn't crush the cap and there's actually not
supposed to be one there? I'm not sure how to deal with this.

I'm also looking for suggestions for the best forums or newsgroups to ask
this.

On Thu, 06 Sep 2007 19:31:44 GMT, Prune
<bobysgotguns_@_yahoo_._com> wrote:

>I'm hoping someone would be knowledgeable enough to help me here.
>Motherboard is Asus P5LD2 Deluxe and I have two sticks of OCZ2P10001GEE
>which I had been running dual channel at 3-4-3-11 and around 950 FSB.
>
>I was having some random crashes over the past couple of days. Looked
>inside and turns out the waterblock on the Northbridge had popped off, with
>the clamp ripping out one of the looped fasteners on the motherboard it was
>attached to. Put the waterblock back but still no dice. After using
>memtest, it turns out that the second DDR memory channel (pair of slots) is
>gone--the same RAM module would work in the A slots one but not the B
>slots--errors in the second, with error rate seeming to be somewhat
>proportional to the FSB frequency I set in the BIOS.
>
>Looked under the waterblock again and it looks like there's a missing
>surface mount ceramic capacitor. I think I may have crushed it while
>reinstalling the waterblock. So either from overheating or breaking the
>cap, some damage appears to have occurred and now I can only use one of my
>1 GB sticks D: It's sure strange though that the second channel slots work
>at all; I wouldn't have expected a partial failure with error rates
>depending on the FSB...
>
>My question is, can I just replace the cap I think I crushed with a random
>one, or maybe unsolder one of the others around it and measure its
>capacitance with my LCR meter and use that, in the hope of restoring
>function?

Yes, this latter idea is the best, though some other caps
that look the same size aren't necessarily the same
capacitance value, but "might" be, or you could randomly
pick a cap value and try it, something like 0.01uF might be
a good place to start. Desoldering very small surface mount
caps can be difficult with a soldering iron, personally I
prefer hot tweezers or to liberally apply flux to the area
and then heat up some soldering braid d****d overtop of the
cap, lifting the whole thing up all at once. Because
desoldering and resoldering a separate cap is twice the
work, I would probably try adding a 0.01uF to the spot where
the prior cap was first/instead of trying to remove the
other one yet... and of course, then test it with
memtest86+. Another option would be to at least try to
measure the capacitance of a seemingly correspondant cap
while it's still in the circuit.


>Or what if I didn't crush the cap and there's actually not
>supposed to be one there? I'm not sure how to deal with this.

It would certainly seem to explain why you now have a
problem with one memory slot, unless you have other ideas
about that. I would expect there probably was a cap, but
using strong light and a magnifying glass, you should be
able to tell if there was a cap there. Another alternative
is finding a good picture of this area online. I don't mean
to second-guess your analysis, but are you sure it's a cap
that was crushed or could it have been a resistor?

Regardless, there's probably a correspondant circuit for the
other memory bank and you can get an idea of what should be
there from that.... granted, without a chipset datasheet
it's a bit of a guessing game still, but you might pick up
some hints by looking at what is present.


>
>I'm also looking for suggestions for the best forums or newsgroups to ask
>this.

I don't know if it would help or not, but you might take the
highest resolution picture you can manage and post that
somewhere, not to the newsgroup but rather linking to it
here.

On Sep 6, 8:31 pm, Prune <bobysgotguns_@_yahoo_._com> wrote:
> I'm hoping someone would be knowledgeable enough to help me here.
> Motherboard is Asus P5LD2 Deluxe and I have two sticks of OCZ2P10001GEE
> which I had been running dual channel at 3-4-3-11 and around 950 FSB.
>
> I was having some random crashes over the past couple of days. Looked
> inside and turns out the waterblock on the Northbridge had popped off, with
> the clamp ripping out one of the looped fasteners on the motherboard it was
> attached to. Put the waterblock back but still no dice. After using
> memtest, it turns out that the second DDR memory channel (pair of slots) is
> gone--the same RAM module would work in the A slots one but not the B
> slots--errors in the second, with error rate seeming to be somewhat
> proportional to the FSB frequency I set in the BIOS.
>
> Looked under the waterblock again and it looks like there's a missing
> surface mount ceramic capacitor. I think I may have crushed it while
> reinstalling the waterblock. So either from overheating or breaking the
> cap, some damage appears to have occurred and now I can only use one of my
> 1 GB sticks D: It's sure strange though that the second channel slots work
> at all; I wouldn't have expected a partial failure with error rates
> depending on the FSB...
>
> My question is, can I just replace the cap I think I crushed with a random
> one, or maybe unsolder one of the others around it and measure its
> capacitance with my LCR meter and use that, in the hope of restoring
> function? Or what if I didn't crush the cap and there's actually not
> supposed to be one there? I'm not sure how to deal with this.
>
> I'm also looking for suggestions for the best forums or newsgroups to ask
> this.

Oh, Prune. Just posting this here too.....in case you don't read it in
the other NG. :-)
Prune, apart from telling all that read here what **** you built
(badly, it would seem) into a box & "maybe" crushing a poor
inoffensive wee "cap", what did you REALLY post for? Obviously, by
your admission, you shouldn't be allowed anywhere near a lamp-post
never mind a pc. If you think that you can just grab any old cap to
exchange........well all I can say is......whoever named you
Prune ...............got it dead right with THAT!!!
How about Bragg for a middle name?? :-)

kony <spam@spam.com> wrote in
news:rlm0e3h2691d21s0dm8t4rkaoqm0g8f90h@4ax.com:
> Yes, this latter idea is the best, though some other caps
> that look the same size aren't necessarily the same
> capacitance value, but "might" be, or you could randomly
> pick a cap value and try it, something like 0.01uF might be
> a good place to start. Desoldering very small surface mount
> caps can be difficult with a soldering iron, personally I
> prefer hot tweezers or to liberally apply flux to the area
> and then heat up some soldering braid d****d overtop of the
> cap, lifting the whole thing up all at once. Because
> desoldering and resoldering a separate cap is twice the
> work, I would probably try adding a 0.01uF to the spot where
> the prior cap was first/instead of trying to remove the
> other one yet... and of course, then test it with
> memtest86+. Another option would be to at least try to
> measure the capacitance of a seemingly correspondant cap
> while it's still in the circuit.

Measuring while in circuit makes the LCR meter put a voltage on the cap,
and would likely exceed the voltage some circuits around there can take,
so I think I'll not risk that.

> It would certainly seem to explain why you now have a
> problem with one memory slot, unless you have other ideas
> about that. I would expect there probably was a cap, but
> using strong light and a magnifying glass, you should be
> able to tell if there was a cap there. Another alternative
> is finding a good picture of this area online. I don't mean
> to second-guess your analysis, but are you sure it's a cap
> that was crushed or could it have been a resistor?

I thought of finding a picture, but they all have the usual heatsink on
top of the Northbridge so you can't see that area.

> Regardless, there's probably a correspondant circuit for the
> other memory bank and you can get an idea of what should be
> there from that.... granted, without a chipset datasheet
> it's a bit of a guessing game still, but you might pick up
> some hints by looking at what is present.

The weird thing is the 2nd bank is not completely dead. I can even boot
with a DIMM only in there, but it shows lots of errors in memtest
(higher when FSB is increased), and of course those cause a crash by the
time Windows starts up... my speculation is then that this cap has
something to do with the timing, as a part of an oscillator perhaps, and
thus the value would be important, unlike the case if it's just a DC
blocker.

sandy58 <Aleckie59@aol.com> wrote in
news:1189110936.556429.126360@y42g2000hsy.googlegr oups.com:
> blah

If a capacitor is serving a function simply of DC blocking, as is often the
case, then its value is not critical, often within orders of magnitude.

Since you're so obviously a troll, I'll not bother replying to your posts
anymore unless they change in nature.

On Sep 6, 9:43 pm, Prune <bobysgotguns_@_yahoo_._com> wrote:
> sandy58 <Alecki...@aol.com> wrote innews:1189110936.556429.126360@y42g2000hsy.google groups.com:
>
> > blah
>
> If a capacitor is serving a function simply of DC blocking, as is often the
> case, then its value is not critical, often within orders of magnitude.
>
> Since you're so obviously a troll, I'll not bother replying to your posts
> anymore unless they change in nature.

Oh, SO sad, Prune. .....and your obviously a poser. "Oh, look at me. I
can speak big words. I AM a BIG Prune, aren't I now!!"

On Thu, 06 Sep 2007 20:40:54 GMT, Prune
<bobysgotguns_@_yahoo_._com> wrote:


>> Regardless, there's probably a correspondant circuit for the
>> other memory bank and you can get an idea of what should be
>> there from that.... granted, without a chipset datasheet
>> it's a bit of a guessing game still, but you might pick up
>> some hints by looking at what is present.
>
>The weird thing is the 2nd bank is not completely dead. I can even boot
>with a DIMM only in there, but it shows lots of errors in memtest
>(higher when FSB is increased), and of course those cause a crash by the
>time Windows starts up... my speculation is then that this cap has
>something to do with the timing, as a part of an oscillator perhaps, and
>thus the value would be important, unlike the case if it's just a DC
>blocker.

Since the frequency of errors goes down with decreased bus
speed, it seems more likely it is a matter of noise not
timing as a timing circuit would not work well if at all
unless this cap was in parallel to another still on the
board? You could try to find what looks like a
corresponding cap for the other memory slot and take it off
and measure it, but IMO you should first try a 0.01uF cap as
I'd mentioned previously. If it's a matter of ordering the
parts then you might try several values in order of
magnitude spreads like 0.1uF, 0.01uF, 0.001uF, 100pF

On Thu, 06 Sep 2007 20:43:36 GMT, Prune
<bobysgotguns_@_yahoo_._com> wrote:

>sandy58 <Aleckie59@aol.com> wrote in
>news:1189110936.556429.126360@y42g2000hsy.googleg roups.com:
>> blah
>
>If a capacitor is serving a function simply of DC blocking, as is often the
>case, then its value is not critical, often within orders of magnitude.


While this might be true, if the cap is torn off then unless
remaining debris had reconnected it, it should lose complete
function in the circuit being open circuit. IOW I doubt
it is a DC blocking function.