MSI FX5600VTDR Vmod help

[Kellisra]

Edit2: I've finally cracked the case. A successfull mod. Read through the thread to find out how it was done, or have a look at this picture for an instant solution:
MSI FX5600VTDR Voltage mod

Oh, and all the other info and pictures that was used to make this happen can be found here:
FX5600 Vmod files

Enjoy!


This evening I began toying around with the idea of volt-modding my old MSI FX5600VTDR card, but I could use some advise.

Now, I havent actually made any measurements yet, as I need to get a another psu first, but here's what i've found so far.

The memory on the card is Samsung K4D261638e-TC36, rated at:
Vdd=2.5V
Speed=3.6nS (275Mhz)
Clock frequency = 550Mhz
(Not a great overclocker, but nevertheless)

On the backside-top of the card is a ISL6225CA chip.
ISL 6225CA data-sheet
Now according to the data-sheet this is a dual-voltage controller. I Couldn't actually locate any apparent voltage divider resistors, but the chip was connected with pin 13 to GND, so I know its set up in dual working mode.

My best guess is that its just a matter of connecting a pot of perhaps 10k between the VSEN pin and ground to boost the memory voltage.

The problem is that the chip has 2 voltage outputs and 2 VSEN pins (pin 10 & 19), so which one do I use. And why are msi using dual voltage outputs?
Here's a picture:
MSIfx5600backside

Then the second problem hit as I couldnt locate any chip for the gpu volt, until I noticed something. At the topside-bottom of the card 4 mosfet looking "thingys" are situated. Can these be a simple vgpu regulator. There are 2 different types of mosfets. Located in pairs. Each has 2 little resistors connected that looks like simple voltage dividers.

Have a look at this picture:
VGPUmodpicture

My guess is that its a matter of locating which one provides the vgpu voltage, then replacing one of the resistors with a simple potmeter. Am I right?

When I get hold of a second power-supply I'll do some measurements to check this theory. I'm not holding my hope too high up for major overclocking here. Although I've replaced the stock cooler with a zalman heatpipe-cooler and papst fan, I'm only able to clock this card up to 366/631 Mhz without voltmods (default is 325/550). I've also added heatsinks to the memory-chips. Still, it will be fun to see if I can squeeze a bit more out of this card, so any help is appreciated.

Edit: Found some data-sheets on the mosfets. I'll study these more thoroughly tomorrow:
NIKO P3055LD
INFINEON 12N03L