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: http://www.badcaps.net/forum/showthread.php?t=32872
as pointed earlier, ur culprid is via chipset and its drivers too bad for so much effort on mobo with that chipset hurray for caps
Nope, proven wrong. Aftert the recap of R9100 Radeon and replacing the two mosfets, the SoF2 never crashed for two days of playing. So there IS a improve. Stability is great. Sadly, when I overclock the card to draw more power, then the game crashed in about a hour or so. Therefore I helped a bit the problem, but did not fix it. This also prove that the problem is in hardware, not in software. Also the computer never lock up after post, as it happend before sometimes. So... more mosfets to replace I quess. And yes, the caps are very nice!
PieEyedPiper - thank you. Sadly, we are not at the end yet... I will now need to replace the mosfets to find the one that matter. These two aren't the culprits. Maybe the low overclock (200 to 206MHz? Come on!) is a point to crapy Northbridge powering, that might lead into the very same results? Because Furmark worked stable, it might give me this idea before... but I failed there. Never the less, I'm not giving up yet - I also have no other option, so I have to make this work. anticupidon - thank you. However I would be more skeptical about hiring a person, that cannot repair hiw own computer I don't think I'm good enought. I just did not have the result... Right now I wonder, for example, what is the operation voltage of the VIA P4M800 - if I know this, then I will know very easily witch mosfet provide the NB voltage and I go after him (and perhaps I can even look, how the voltage is supplied, so I could increase it a notch or two to make the mobo stable even overclocked - 206MHz is not a overclocking) One way or another I got to get this fixed!
Jeez, there is a stack of dead motherboards sitting in my office that I should send you.........nice work mate. Btw where do u get the parts from?
If these mainboards are somewhat interesting, then my all means... PM me for address I get parts mostly from Digikey or Mouser. I mostly have first to determine what voltages there are and then determine the best caps to put as in replacement. Not that hard, when the hardware is possible to turn on at least. And I'm not done with this machine, no way! It is going to work well... I will see that happening!
