EP-4PDA2+ Vcore mod

[AndrOvr]

Hiya there,
I have the EP-4PDA2+ mobo, and the max vcore I can get out of it is 1.57v idle and 1.52v load. when 1.6v is selected in bios (max)

I need atleast 1.70v.

Here's the datasheet of the volt. controler.
http://www.semtech.com/pdf/sc2643vx.pdf

Anyone?

[AndrOvr]

...

[AndrOvr]

One more

[Mr.x3m]

I need it to! but i hope this help us :D


Originally Posted by dracula from Aoaforums


Hi
I have no personal experience from 4PDA2+ but I looked that pdf and I
can only make some suggestions what to try. No one of my friend have
this mobo at the moment so I can not test any of my tips on it.
There are several pins that will affect output voltage:
VID 0-5 inputs that tell the controller cpu's required voltage
OUTSEN (23) one of the voltage sense pins (this is for current balancing
but can affect voltage too)
FB (7) this is major voltage FeedBack pin that is used for voltage
sensing
ERROUT (5) is voltage error amplifier output and this can be used to
tweak voltages
Best way to mod is to make vid pins user configurable (or atleast a few
of them)
First, what cpu are you using. If you use a "new" P4 then it could use
VRD10 voltages (page 8) and maximum is 1.6V what you can set from vid.
If you use older P4 then it uses VRM9.x and goes up to 1.85V (page 7).
If your cpu's default is 1.5V vid lines are (from 4 to 0) 0,1,1,1,0 and
if you ground vid 3 so you have 0,0,1,1,0 your default voltage is 1.7
look page 7 of pdf. This is the easies and most secure way of tweaking
voltages. Best way is to use 0.5K to 1K resistor to groud them. Check
controllers pin 11 (vid 3)
I assume that FB line (pin 7) from controller is hardwired to cpu socket
(no resistors) so motherboard cutting is nessessary if this is tweaked.
This should be the last to try if anything else is not working.
Basically you have to cut motherboard trace and solder a resistor over
the cut and another resistor from FB pin to ground. These resistors
should be pretty small, about 10 ohms over the cut and about 100 ohms
from FB to ground (10/(10+100)) gives you 9% more voltage.
Setting proper resistor from errout pin to ground can be used to tweak
voltage. You can put a 100K potentiometer to this and start to
decreasing resistance and look if there is any changes in voltage. If
you have to go below 1/3 settings at potentiometer then you should
change smaller one and continue from there. I suggest that you test this
with some cheap cpu first because there is a possibility to kill it with
too small resistor and overvoltage.
I suggest that you try to mod those vid lines first and see if that
works.
Look your cpu's Sspec.

[ReaLDjiNN]

hi guys i need this mod too and ive got some pics
http://img211.exs.cx/img211/3692/ep4pda2big1ug.jpg
http://img200.exs.cx/img200/7521/mod7ho.jpg

[persivore]

Can you get the resistance resistance between pin7 and a Vcore read point, such as a Vcore inductor, and pin7 and ground please.

[ReaLDjiNN]

how can i found vcore inductor and a v core read point :confused:

[persivore]

I've circled the Vcore inductors. There should be some exposed metal/solder at the base of the inductors, where they are soldered to the front of the board. Use one of these points as the Vcore read point.

[ReaLDjiNN]

I've circled the Vcore inductors. There should be some exposed metal/solder at the base of the inductors, where they are soldered to the front of the board. Use one of these points as the Vcore read point.
can i chose whatever one of them???
can you send me your msn or icq for details when i do this mod ill show it in forum

[persivore]

You can chose any of the inductors. I've sent my MSN details by PM.

[ReaLDjiNN]

tahnks very much for your helps :)