First of all i will start by introducing my little monster:
The motherboard (you already know it,it’s all about it ;-) ) :*Asus M2NPV-VM, you know the specs.
Processor: AMD Athlon64 X2 3800+, 90nm, original 2000 MHz, I think power enhanced (60watt conso)
Cooling: Arctic Cooling Freezer 64 Pro, max 2500 rpm
Memory: 2x1Gb DDR2 G.skill HK PC6400-800Mhz CAS 4-4-3-5 CR2, stock volt 2.0-2.1 V
Graphics: PALIT Ge9600 GT Sonic
HD: Hitachi 250 Gb SATA2
I added to this:
- a chassis fan Arctic Cooling 8cm, 2500 rpm ( I love this brand ,their fan are extremely silent)
- a chipset fan 4cm at 4500~5000 rpm,
I modified myself to fit over the north bridge chipset heat-sink, this is a must to be able to increase the core frequency,
You may know already about the overheat problem of this mobo( at stock freq it sometimes locks due to overheat of the north bridge)
And all this (dvd included) is powered by a standard 350 watts power supply
I wonder why people by 750 Watt power supply !!!
( pic : motherboard.pic )
Let us now come back to our chips !
I will explain step by step and be little bit verbose on how I ended to this mod, this to help newbies understand, create there own mods and post them like I do, since I spent too much time to find out my way.
Expert will be bored, sorry
.
On the picture the green boxes are the one we will be interested in, the bleu ones are spots for further mods(Vcore , 5V, 12V , Vchipset … etc)
1 – Start point:
As I found in a forum start by identifying the chips in the neighbourhood of the ddr2 socket,
Write down the reference and go find the datasheet.
2 – Identify the chip:
The first I suspected to be responsible of volt regulation of ddr2 was the RT9173,
Further test showed that it seems to be attached to the 5V rail. So search again.
Dig into the forums led to the LM324 that sometimes is used for VR, but its output voltage was not the one I look for; 1.8 – 1.9V… Further research ended to the RT9214 chip
( pic : vddr circuit.jpg )
( pic : rt9214 typical.jpg )
And as you can see the onboard circuit shows a lot of similarities with the typical application circuit.
The red leg is the pin 6 (the feed back)
The green resistor is attached to GND so it’s our R2 (the one we have to pencil to reduce its resistance and therefore increase our Vddr)
The blue line could be an unsoldered capacitor.
The yellow resistors are to not be modified, since they are attached to Vout and in our case to a not soldered capacitor and then to the mosfet shown here next.
( pic : rt9214.jpg )
Vout and mosfet deliver little bit lower than the Vddr voltage rail (1.85V for a 1.9V and 2.0V for a 2.1V)
Measure of the equivalent resistor between leg 6 and GND gives a stock value of 512 Ohm
3 – The modding part:
Here comes the “Pencil Art” time, despite the fact that the area is not easy to access, choosing the right pencil is very important, HB pencil could do the job, but you need to choose the right one with enough lead concentration.
( pic : HB pencil diff.jpg )
As shown in the picture you can notice the difference between the two, I first used the green pencil, pencilled over R2 and in absence of digital multi-meter the result was a disaster, no Vddr increase at all.
Afterward I found out that R2 dropped to about 508 Ohm, not much!
And the best I could get with a lot of pain is a drop to 475 Ohm.
So I used the other, and surprise!! First attempt, couple of strikes and I’ve got a drop to 438 Ohms.
Great.
4 – Relation Ohm-volt:
I proceeded to different measurement and wrote down the results
R2(Ohm) + Vddr(Volt)
-----------+---------------
....512....+......1.89
....497....+......1.94
....475....+......2.03
....457....+......2.10
....450....+......2.14
....438....+......2.21
....429....+......2.23
-----------+--------------
that's it ,i hope this have been helpful for the M2N PV-VM owners
any more question please ask
bye
n.b. :
PICs uploaded in order
- hb pencil diff.jpg
- motherboard.jpg
- rt9214 typical.jpg
- rt9214jpg
- vddr circuit.jpg