Now about mods. I couldn't find any documentation on two unpopulated pin headers on the card - output and speaker, but I would assume one is line level output to connect to the AUX port of a second card, and the other is PC speaker. Both have unpopulated SMD components around them:

Does anyone have experience with these? It is said that MX300 isn't too far from the reference design. Does anyone have schematics for the reference design? Or a different model with these ports populated?

In case anyone's interested, the two missing capacitors are 10uf 16v solid state electrolytic caps, which I replaced for 10uf 25v caps because that's what I had on hand - they handle only 5v vdc and they didn't blow up or anything, but were removed from the pads - likely because the card got banged up against another card.

The smashed capacitor is 470uf 16v Nichicon, which I replaced for an equivalent Sanyo cap I had laying about.

Not gonna run tests today because it is a bit late - will report back tomorrow.

Funny, I got one that was pretty mangled too. Except mine is missing the slot bracket entirely, and I had to transplant AC97-coded jacks off a CMI 8738 card.

Gotta test it tonight. I genuinely wonder if all the work wasn't in vain for me. Also had to replace a few missing caps.

PcBytes wrote on 2025-02-12, 17:07:

Funny, I got one that was pretty mangled too. Except mine is missing the slot bracket entirely, and I had to transplant AC97-coded jacks off a CMI 8738 card.

Gotta test it tonight. I genuinely wonder if all the work wasn't in vain for me. Also had to replace a few missing caps.

Keep me updated 😀) these are pretty nice cards, and from what I've seen they can take a beating. Mine was working with all the missing caps - at least 3 of them were on power lines, filtering the bus noise.

Here are the caps I replaced.

This is one of the boards, the more you look at it, the worse it looks. First I noticed the big 470uf cap was mangled and perforated by impact. Then I noticed a missing 10uf cap. Then a second one. Then three more.

The new mangled "bracket" was shorting the output connectors.

I wonder how this card got to this point.

Reporting back to confirm that the Diamond Monster Sound card is alive and kicking.

Yeah, mine seems to be entirely dead. Any board I stick it in will stop POST-ing unless I remove it.

AMI: 13 12
Award: 25 24

I recapped mine entirely, no dice. Oh well, didn't have high hopes given how mangled it came to me. (worse condition than yours)

PcBytes wrote on 2025-02-13, 15:28:

Yeah, mine seems to be entirely dead. Any board I stick it in will stop POST-ing unless I remove it. […]
Show full quote

Yeah, mine seems to be entirely dead. Any board I stick it in will stop POST-ing unless I remove it.

AMI: 13 12
Award: 25 24

I recapped mine entirely, no dice. Oh well, didn't have high hopes given how mangled it came to me. (worse condition than yours)

Did you check for shorts to ground on PCI power lines?

https://pinoutguide.com/Slots/PCI_pinout.shtml

Can we get photos?

Also, even though I couldn't find data sheets for AU8830, we could use my working card to cross-reference and find out what's wrong with yours, if it's worth it to you.

Traced all my steps back across each cap. I assume there's something with the chip itself at this point, as I have zero shorts anywhere.

The card, a bit after I finished replacing the destroyed audio ports on. The only difference at this point is all caps being soldered in place of the missing ones, including a few near the CD headers that were looking a bit suspect.

I just chucked it in a deep corner after failing to fix it so getting it out might be a challenge.
As is the current GA-5AX r5.2 I have to fix a exploded MOSFET on... which might have taken out the RC5051M next to it, as the board was shorting every set of FETs I gave it.

PcBytes wrote on 2025-02-13, 18:31:

Traced all my steps back across each cap. I assume there's something with the chip itself at this point, as I have zero shorts a […]
Show full quote

Traced all my steps back across each cap. I assume there's something with the chip itself at this point, as I have zero shorts anywhere.

The card, a bit after I finished replacing the destroyed audio ports on. The only difference at this point is all caps being soldered in place of the missing ones, including a few near the CD headers that were looking a bit suspect.

I just chucked it in a deep corner after failing to fix it so getting it out might be a challenge.
As is the current GA-5AX r5.2 I have to fix a exploded MOSFET on... which might have taken out the RC5051M next to it, as the board was shorting every set of FETs I gave it.

I cross-referenced it with mine, if you feel up to keeping looking at it, I could put my card in a computer, turn it on and check the voltages on the pins of the chip itself.

There's two things that would need diagnosing at this stage: the continuity between the PCI pins and the audio processor chip, and the power delivery to the audio processor chip. At that point the card would need to start up, even if it outputs no audio.

That's the thing - the card itself prevents ANY board I have from POST-ing at all. That's why I wrote it off - even with all caps replaced, it did that.

Well, sometimes it is healthier to just throw it in the far corner to maybe return to it some other day 😀) cheers.