Hi!
I'm a noob to this page, to vmodding but I think I have an useful method and I want to share it with the Others(Lost ownz
). So as I wrote to Urlyin in my e-mail(btw he's the one who encouraged me to write this down here, so thanks for that
).
I decided to do the pencil vmod.
The main problem with the original pencil vmod technique that graphite only can be applied in a very thin layer, therefore it's conductivity is quite poor. So I thought somehow graphite powder should be applied on the place of the missing resistor.
So I made some powder using a sharp cutter on my mechanical pencils 0.5mm lead (I think it's HB graphite, not 2B, or I tried this with 4B pencils but HB was better), then I put only 1 or 2 drops of water in a small pot (actually it was the lid of a little bottle with a very short rim on it, so it was perfect in size to contain so little amount of water). After that the powder was dispersed into the water and I mixed the whole thing with the lead of my mechanical pencil.
The HB graphite's powder is so refined that it only floats on the water, but it's possible to get some water and graphite powder aswell on the point of the pencil and after this, it can be literally painted with the point of the pencil between the two solder pads. After the water evaporates there's a perfect graphite bridge (and it sticks well so the air movement can't blow it off, but it's easy to remove it - for example with a little rubber) between the pads and it's thick enough to lower the resistance even to about 380KOhm(this is what I measured) from the original 430KOhm.
Finetuning the resistance is easy too. Again with the point of the mechanical pencil the width of the bridge can be reduced, so the resistance will increase.
I myself tuned the resistance to about 400KOhm, the core voltage is about 1.51V now. The original was 1.41V at 430KOhm.
I have a PrimeCooler PC-VGAHG1 CU on the card - VF700 is out of stock everywhere here (Hungary, Budapest) so I bought this.
Btw this 0.1V means, the core is stable on 575 mhz instead of about 545mhz.
With the stock Cooler on 500mhz core the temperature was about 80C°.
Under load the core temperature climbs to 64C°(~560mhz,62C° with fullspeed fan) now. It was about 60-61C°(on lower core frequency~500mhz) before the Vmod so I think it will be OK on the long run.
Now the next step to get some air movement on the upper side of the card, because ram heatsinks are running a little hot on that side.
I hope this graphite painting thing will be useful for others who have problems because of the missing R1597.