MSI PM8M3-V recap

MSI show on it's website this image, of a MSI PM8M3-V mainboard:

As you can see, the Vcore output is populate with 7 Oscon polymer caps. In reality, however, you get this:

A strip down version, from 7 caps to 3 (!)… and that is for the power hungry P4 CPU's! Yes, there are also the two top caps, but they are not polymers and even the another top two up are Vcore connected (3300uF 6.3V)...
But the main rip off is the caps type used. They are OST 680uF 4V caps, so not a good caps by any way 😞 In short, they show you seven polymers, but deliver there OST crap caps. Is not that irony?

To make this post more usefull, the caps list for MSI PM8M3-V goes as follows:
5x 680uF 4V d8 OST RLA (+4 leftovers)
2x 3300uF 6.3V d10 OST RLX
3x 1000uF 16V d8 Panasonic FL (+1 leftover)
12x 1000uF 6.3V d8 OST (+4 leftovers)
2x 470uF 10V d8 G-Luxon
1x 10uF 16V d4 SMD

Mine MSI PM8M3-V is PCB v. 1.0. Only there Ost caps on side, FOUR missing! That is stealing by MSI marketing!

AGP powering is rather underpowered, not to mention NIKOS mosfets bad rep:

Ram's run on Ost caps too, completely:

Vcore is supported with big 3300uF Ost caps (and two small Ost caps nearer the socket LGA 775 on top):

Near NIC (Realtek RTL8100C) is G-Luxons (!) … a terrible known bad caps. Unacceptable!

The Vcore input have space for 4 caps, just there are used and they are Panasonic FL caps, witch cannot be bought on Digikey and I did not suppose they are even original Panasonic caps… What is worser is, that they are d8 only, while 16V caps are hard to source even with d10, not to mention d8...

So this obviously cannot stays like that, because the mobo is starting to shown first unstability issues and crash on load, so, there had to be recap. I also wanted badly to give the mobo back the nice polymers, the MSI marketing striped it off… In short, I wanted to trumph out the advert 🙂 Because even better that Sanyo Oscon polymers exist - and that are Nichicon LE polymers. So I made my list of ideas, how the recap shuld look like:

9x Nichicon LE 820uF 2.5V d8 493-3058-ND
2x Nichicon HZ 3300uF 6.3V d10 UHZ0J332MPM-ND
4x Nichicon HZ 1000uF 16V d8 UHZ1C102MPM6-ND
16x Nichicon HM 1000uF 6.3V d8 UHM0J102MPD-ND
2x Nichicon LE 470uF 6.3V d8 493-3066-ND
1x Taiyo Yuden 47uF 6.3V 587-3406-1-ND

However certain things go wrong. The first was, that I managed thru friend to order only the original number of the 1000uF 6.3V caps, 12 of them. I had to improvise and replace the remaining 4 unused before with the Samxon GC caps, witch is similar is quality, tested good caps.
At lest I see what caps are new there, lol.
However worser was, that the only one d8 caps for 16V was really hi-end elytes Nichicon HZ, but they are out of the stock for months. So, what to do? I had no chance but to press on and thy some improvisation there...
And at last I completely forget the little SMD cap behind the AGP slot, witch I indented to replace with ceramic caps, when there is available even 47uF ceramic SMD caps with the little 12210 size!

So the main idea was to get the Vcore voltage filtering on hi-quality level, witch I managed easily by using the best polymers ever produced (nothing beat their ripple current rattings):

But now what to do with the input caps, that are not stock? In the end I managed to squeeze easily in their places (luckily, there is nothing upclose near them) replacement caps, witch I took from my stash - a  Panasonic FM 1000uF 16V d10:

Of course I added even the unused one, right after the input coil:

Ram's get a quality Nichicon caps too now, so they cannot complain on discrimination changes:

What I also did miss is the sad look of six empty places, where a good quality ceramic caps should be, so the Vcore will be stable even in extreme situations:

As I mentioned, on the previously unused places I slap the Samxon GC caps:

And the NIC controller must be jumping out of joy, because it got the quality Nichicon LE polymers voltage filtering instead of the G-Luxon crap caps - now this is a jump in quality!

Over on the CPU socket, there come together two important caps. A Nichicon HZ - the best electrolyte caps ever when come to the ripple current (Samxon GA are par to par with it, but nothing other come even close, not even Rubycon MCZ, yet the Man Yue stoped manufacturing them 😞 ) and then the Nichicon LE - best polymer ever made:

And at last - overal look on the Vcore regulation - now it look far much better that before!

And the result? Well, the CPU and rams and HDD is working perfectly. The Vcore regulators, with the serious heatsinks, are - even that no fan is blowing at them, yet I removed the serial and parallel ports to get them better ventilated - after a day of work, night of stress test and half day of gaming heardly even warm…!
That well shown the fact, that quality caps means lesser temperatures of the components. That was just great. And with stock box fan and no case fan...!

Now just the AGP cap and some of these ceramics...

I managed to replace the last remaining capacitor on the MSI PM8M3-V mobo - the 10uF d4 SMD suxxka, that have kinda horrible ESR or 3.2 Ohms:

…with a new SMD tantal-polymer KEMET 220uF 2.5V capacitor T520B227M2R5ATE015

…with have ESR around 0.015 Ohms 😄

That should be a huge improve. Also I, out of the desperation, resoldered a bit the drain tops of there NIKOS mosfets near the AGP slot.

And result?


So it looks like that the mainboard was not up to the blame the whole damn time. It is the videocard that have to be recapped.

The Radeon R9100 was crashing when new SoF2 level is loading. Given that it run passively cooled on Licon caps:

…with 60 mOhms ESR one should not wonder. Rest of the caps looks quite similar, so recapping is in order, just waiting for the caps (as usual).

The PNY 6800 GT failed after a short time to run in AGP mode, going down to PCI mode and crashing after some gaming is played. Now that is serious problem, because there are just THERE caps, two of them polymers on the voltage input filter and they are Chemicon polymers.
Last one is unknown 100uF SMD cap and that it is for other that ceramic caps! I would be inclined to add some caps in the blank spots too, probably something over 100uF SMD… and I would also like to create a custom effecient heatsink for the mosfets on the card, because they do overheat a lot - GPU VRM temp 71°C: View image: temperatures after 30min

Should I try recap these graphic cards before I try replacing the NIKOS mosfets?  ???

Also there was a suggestion that the regulating mosfets are maybe not up to the task. So from this very interesting link:
Vishay - MOSFETs - N-channel - DPAK (TO-252) package
…I choose this one:

Vishay SUD50N02-09P
20V, 17mOhms at 4.5V, 15A, rise time 10nS, shutoff time 25nS
gate charge 10.5nC, gate treshold 0.8V

Slightly slower, but good total gate charge as well, as sensitivity - that should do the trick.

Even that at 4.5V the resistance is actually 17mOhms, then it is still far better that 50mOhms.
Also the mosfet can operate at 175°C, witch is pretty high.
While it is a bit slower (rise time 10 to 6, shut off time 24 do 20), the gate treshold 0.8V should compensate that a bit for the original is 1.2V… The gate charge 10.5nC over 15nC is just perfect.

I believe I found the perfect replacement, that is better than the original! (Sadly, they come with "enhanced" version Vishay SUD50N02-09P-E3 and now the supply only the E3 versions... the specs are exactly the same, EXCEPT total capacitance of the mosfet. That jumped from great 250pF for the SUD50N02-09P (original NIKOS P3055LDG had 450pF) to whooping 1300pF for the new E3 version... Well, so much for E3 version!) So when everything fail, then... this?

Today is the day! 🙂 UPS delivered a 10pcs of Vishay SUD50N02-09P-E3 mosfets samples from German Vishay HQ. Hoooray!

Therefore I immediatelly went to work. First at all, there is a picture that show the "polymerization" of caps near the AGP on the MSI PM8M3-V mobo:

The remaining two non-polymer caps (Nichicon HM & Samxon GC) run at 5V, so there is no good substitute for them, but for the rest, the capacity was bumped (2x 1200 & 2x 2200uF) as well as the specs.

The yellow KEMET tantal-polymer 220uF 2.5V cap is also well visible, as replacement for the 10uF 16V SMD suxxka cap 🙂

However that did not helped, so it is a time to replace the NIKOS P3055LDG mosfets. I picked (for the start), the two, that are most suspicious: the two most close to the AGP slot - the left one delivering the 1.50V and the right one 2.50V to the AGP.
(as you remember, lowering the 1.50V voltage from default 1.55V helped considerably with stability, so it is not like I picking up on random mosfets)

Sadly, the place is pretty crowded, so I had to pull the caps off first:

And as you can see, there are new Vishay SUD50N02-09P-E3 mosfets soldered in! I did not skip on the tin, as you can see, trying to lower every possible mOhms out… 🙂

And then I soldered back and... tried the mobo. Worked right away, hooray! (with Riva TNT) Then I tried with my R9100 and it also worked well, so I pulled the machine together and now I typing on it, as you can see 😄

But first news is bad news. There is no instant "back to AGP mode" in Win. Still it show PCI mode, so I probably have to reinstall the graphic card to get again AGP mode back, as I always had it, before the crash during gaming...
So no instant fix.

But since it crashed by playing in PCI mode too, then I first try playing, so I can determine the stability. If anyone can cross a finger or two (or even say prayer, tough I cannot believe in anything these days), it might help 😉

Mosfets choices: