vMCH pencil mod for intel D975Xbx Bad Axe

Plester · 09-29-2006, 10:35 PM

at your own risk...

just my 2c, but when i pencil mod, i take the initial reading, pencil, take a reading and when i am happy, vacuum the graphite dust, take another reading, and if it is all good, slap a small piece of tape over the area.

I lowered the resistance by 10 ohms from 330+/- to 319, and when 1.725v is set in bios, i get 1.82v actual w/ dmm. Now stable at 450.

eva2000 · 10-04-2006, 08:40 AM

awesome... anyone else try this ?

do you have a top down photo of the area to pencil ?

where's the vMCH read point for DMM measuring ?

thanks

Plester · 10-04-2006, 11:55 AM

here is omegas? pic.

Darkenreaper57 · 10-05-2006, 10:25 PM

Is that blue box called a "trimmer"? I'm still rather new to electronics, but am trying to learn more about parts as a EE major. Unfortunately in classes, they don't expose us to real-life circuit elements enough.

toddm27 · 10-16-2006, 07:51 AM

hey just curious, but when I measure with a dmm, at the spot indicated if set to auto in bios, I'm only getting 1.3v, and when set to 1.725, it only gets 1.6, is that spot acurrate or is my board def? the spot circled is where I'm measureing from

before · 10-19-2006, 11:01 AM

That's the appropriate spot

Looks like why Bad Axes are so FSB limited; my r.302 gave ~1.55Vmch for 1.72V set into the bios... BTW mine took Spi1M @ 450FSB for ~ 1.55V as observed with 2 different DMMs.

I've got the same issue with Vddr (for instance it was ~ 2.08V DMM for 2.2V bios)

eva2000 · 10-20-2006, 08:19 AM

Okay did this vMCH pencil mod on one of my D975XBX Bad Axe rev304 ICS based boards

Default - only measured 1.725v bios setting
bios setting -> bios value -> dmm value -> IDU value
1.725v -> 1.671v -> 1.689v -> N/A

pencil vMCH modded
bios setting -> bios value -> dmm value -> IDU value
1.725v -> 1.736v -> 1.744v -> 1.745v
1.650v -> 1.671v -> 1.670v -> 1.680v
1.600v -> 1.620v -> 1.628v -> 1.628v
1.525v -> 1.555v -> 1.615v -> 1.563v <- weird ???
default -> 1.555v -> 1.615v -> 1.563v <- weird ????

Before pencil vMCH mod max fsb on this board was 421-423fsb (1067fsb strap) and 426-429fsb (1333fsb strap) using Thermaltake Extreme Spirit II chipset cooler.

Have yet to test new max fsb for this board.

before · 10-24-2006, 01:53 AM

It seems me a pretty good work buddy

That's good to have a little higher voltage than what the bios reads because of the droop while the system is loading. In a sense, the bios setting is an average value.