GA K8NSNXP-939 Vmods

[Hell-Fire]

There is a thread already posted about this board, but as I have said in other threads of mine, I am in the process of trying to clean up (organize) the forums in order for our members to get the information they need to complete the mods without having to look thru page after page of material.

Kyosen made a post showing pics of his mods, but he did not specify the VR values needed as he had previously sold the board. I did these mods about a week ago I guess, but never got around to posting about them as I had been swamped modding for members, went out of town, and got pretty sick from moddin' fumes. Thanks to STE for his idea about using a 120mm fan for outtake.

It is then up to them to read the entire thread for other important information.

On to the mods:



I had previously done the mods, but decided to unsolder the wires to make things easier to view for this thread.

The K8NSNXP-939 board has the W83301GR vreg onboard to control Vdimm and Vbt (Vtt). This is just a variant of the controller that is on the Abit NF7 boards.

Vdimm Mod:

This pic shows better than words can describe on how to do this mod. Set the VR to max resistance before soldering into place.




Just like most boards, you can also do the Vdimm mod using the 3.3v Rail method. There are several points where you can connect the wire from the ATX punch thru to the available capacitor legs that are in the Vdimm circuit.

I used the point that is furthest away when testing the mod, but I am sure the other 2 points that are close together will work just as well since all 3 capacitors are connected.

You only connect to ONE of the capacitor legs.




Vtt (Vbt) Mod:

Same as above. The pic shows how to do the mod. The base resistance is around 1.640K ohms, so a 10K Ohm VR will lower the reistance by 230 ohms when first soldered into place. I personally used a 20K Ohm VR as that only lowers the resistance by 125 ohms when the mod is first soldered into place.

Obviously the more the resistance is lowered from the start, the higher the starting voltage is going to be. Set the VR to max resistance before soldering into place.




Here are the the Vdimm and Vtt read points:





Vdd Mod:

First off, I need someone to verify this mod for me. Please confirm that I have the proper Vdd read point marked. I am pretty positive that it is correct, but confirmation from someone with a running board is always a plus of course. Any value VR between 200-1K ohms will work nicely. Obviously the closer you can stay to 200 ohms the better as adjustment will not yield as fast a voltage increase per turn. I would really apprec someone testing this mod for me so I know that it is proper...cause if not I need to edit this and remove it until we find out more about it. Again, I am fairly certain it is correct.

This involves a trace cut as I couldnt find a suitable location for the mod on the topside of the board. As far as trace cut mods go, this is a fairly easy one honestly.

The trace runs away from the capacitor "+" leg that is part of the Vdd circuit, and runs into a clear area that is perfect for cutting the connection as other traces are not nearby.

Set the VR to zero resistance before soldering into place, and yes, you need to use all 3 legs of the VR.





Here is the Vdd read point:





I would like to hear from members running the A64 rigs about whether a VLdt mod is worth researching on my next A64 board modding adventure. I do not own an A64 board, nor have I had the time to do the reading that would tell me what this VLdt is responsible for on this rigs.

Any input from members that have a running board is always appreciated.

Cheers.