8800GT voltage mods

[jason4207]

The solder on the resistor to the right was an accident after I cleaned everything up, it never touched anything else, though.

I never cleaned the board, but the soldering iron was clean. I'm sure the soldering iron wasn't on too long, I added a small drop of solder to the tip of the wire, then held it in place and heated it until the solder melted.

Yeah, the 700 ohms was when it was all in place. What do you mean by the whole circuit? A vGPU point to ground, or..?

I did the opposite you did, clockwise = more resistance, and since I used a 1kohm VR, I decided to start at ~700 because of the previous BIOS vmod. Never really got a chance to play with the voltage, though

When the mod is in place it is impossible to measure the resistance of just the VR. There are other paths for the electrons to take w/n the circuitry on the board, and you will be measuring the accumulated resistance of all those possible paths to ground. When you measure the main solder point to ground (or just try to measure the VR while it is attached to the board) you should get somewhere b/n 10-15Ohms. I'm getting 11.1Ohms right now at 1.35v idle. If you're reading 700Ohms something is definitely wrong unless you have removed the VR or it isn't connected properly.

I don't think it matters that you did the BIOS mod as I did the same thing. I do know that the 500Ohm is a little better to use, but you should be able to get by just fine w/ the 1k. It always best to tune to max resistance before you attach the VR b/c the more resistance there is the more it is like there is no mod there at all. Infinite resistance already exists b/n any 2 given points on the board through the air, so adding a high value resistor has the least amount of effect on the overall circuit.

I prefer to get it setup where turning clockwise increases voltage just b/c it is easier for me to remember. I also did the vmem buck mod to reduce memory voltage, and since decreasing resistance decreases voltage w/ that mod it is wired the opposite way, but the end result is that I turn counter-clockwise to reduce the vmem voltage. It doesn't matter which way you do it as long as you remember it correctly. Of course if your watching the voltage w/ a DMM you'd know pretty quickly which is the correct way to turn.

Here's a pic I borrowed from earlier in the post...thanks Dinos22!



You can see the trace in question. Make sure you have full connectivity from the IC leg all the way to the main solder point or at least to the last resistor. I'm not sure where the circuit or if the circuit continues below the surface to a lower level, or if it just travels through the SMC/R's from this point, but if you don't have full connectivity along the red trace I drew the you could at least try and make a solder bridge to reconnect and possibly save the card. All points along the red line are the same point in the circuit.