vCore mod for ASUS M2N68-AM ??

[Tommie_lj]

someone got a mod for this budget board? it has very limited settings in Bios, only standard, +50mv, +100mv..

i can fix highres pictures of the card if needed.

I Reeeeeeally need help on this one...

/Tommie

[hema]

sure you need to post clear photo for the cpu power area clearing the type and the serial of voltage controller chip

[Tommie_lj]

the problem is i dont have a clue wich one is the controller chip!! :S i checked them all up a month ago, but i couldnt understand wich one is used to control Vcore.. is the chip usually near the mosfets or can it be on the other side of the card?? do you need all the serials, cus some of them is extremely hard to read..

i can fix the high res pics tomorrow.

[Tommie_lj]

i post pics tomorrow.. going for barbeque party tonight ^^

I think RT8855 is hte controller chip. richtek is the manufacter, and i have asked for the datasheet for the chip, since i cant find it anywhere..

[Tommie_lj]

http://www.file-upload.net/download-...55-00.pdf.html

This is the Datasheet for the RT8855, and pics of the chip itself.

now help me with this little mf, his crying for some vcore

[ceemic]

Measure resistance between pin12 (FB) and GND. To do that, You have disconnect all hardware and power cables from board, including CPU.

Btw, where did You get that datasheet?

[Tommie_lj]

ceemic, i will measure the resistance in 5 minutes. back with measurements as fast as possible.

do i need to dissconnect the gfx card aswell? ram?

[ceemic]

I recommend removing everything...

[Tommie_lj]

here is what i found out..

the reason i did two measurements is i am not 100% sure where they marked the "1".. but i guess the 10Kohm reading is from the correct leg 12.

the 10Kohm reading was very slowly increasing while measuring.. wierd ?? Blue dot is connected to pin 12, and reads the same. so if this is the leg to mod, thats is a good soldering point.

if i measure V on one of the mosfets i get 1.516V, CPU-z reads 1.472V. is this a good readout point??

do you think cpuz will see the increased voltage, or will i have to use the multimeter while adjusting?

[ceemic]

Yes, that 10k place is right. PS. can You measure resistance between pin12 and pin3 (FBRTN) also?

If Your measurement was right, then 200kohm VR is safe to use.

You can use coil and cap legs also to measure Vcore. But You can access them only otherside board. So You can compare the readings You got from mosfet legs.

[Tommie_lj]

i have a 100kohm VR on hand. im not afraid of destroying the cpu, im going for the Phenom II very soon anyway..

will make the measurement right away, so check here again in 30 minutes..

[ceemic]

Yes, You can use 100kohm VR also. Just the "def" Vcore jump will be bigger. But for 24/7 You can use lower value in BIOS therefore...

[Tommie_lj]

okey

the reading between leg 3 and 12 was pretty much thesame as 12->GND. 10kohm, and slowly increasing. maybe its a cap or something in the circuit being charged by the mm?

i changed vCore in Bios to the standard setting, and measured at thesame mosfet, and got 1.415V. i think i will use this as a vCore readout point.

[Tommie_lj]

IT WORKS !!!

Blue cirkle->100kohm VR->GND

Def jump in vcore is 0.06V with this VR. not a huge jump, and for most users i recomend this vr, to gain control.

Even CPU-Z reads the increased Voltage in realtime!!! Great success ^^

Thank you Ceemic for your help /Tommie

[ceemic]

Nice

[Tommie_lj]

[Tommie_lj]

somehow i recently killed my AthlonX2 Cpu with either to much juice, or else the single turn VR crapped out and made the RT8855 put out exessive Vcore.. i had Vcore set at 1.65V when the screen suddenly blacked out.. i didnt stress the cpu or anything, in fact i was changing settings in BIOS at that moment..

so now i bought a brand new PhenomII 940BE, and i did remove the mod. maybe someday i put a small resistor there to up the voltage a little, but no more playing with VRs on this mobo. im running 3,5ghz 24/7 without a problem, but thats how high it goes with 1.425V.

[ceemic]

...single turn VR...

[Tommie_lj]

yes yes.... i know

[celemine1Gig]

Seems you had to learn it the hard way. But never mind, we nearly all did.
Using a single-turn VR is one of the badest things precision wise, when it comes to vmodding. And you didn't even use a series resistance to limit the max voltage. No wonder you killed the CPU faster than anyone could say "bad idea".

So I hope you'll never do this again.

[Tommie_lj]

it wasn't really a big deal.. i had already planned to buy the PhenomII soon, but not that soon

[ceemic]

...we nearly all did...

Same here
First VGA's Vmod I did was on 6600GT and I used single-turn audio mono-potentiometers. GPU worked fine, but for mem it was too unstable and I killed my card after second day
http://ceemic.pri.ee/hardware/6600gtvmod.jpg (back in 2006)

[Tommie_lj]

ooh lucky you i remember my first vmod. it was a Hercules 3D Prophet 4500 (i think?? ), with a KyroII chip it clocked good with the mod, but it did kind of deinterlace the picture ^^