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Looking for some help figuring out the vgpu mod for this GPU. It is different than all the others I have seen as it is DDR2.
I can measure resistances, can someone give me a hand plz?
http://img145.imageshack.us/img145/7...1761gv3.th.jpg
http://img153.imageshack.us/img153/3...1771tn3.th.jpg
IC markings:
http://img293.imageshack.us/img293/8...xo61kf9.th.jpg
http://img402.imageshack.us/img402/4...rr21rn2.th.jpg
That AT88SC is EEPROM memory, bios probably.
Second IC does not return any results in Google. Make sure you read the markings correctly
Post some clear pics of card's front, areas around typical suspect ICs.
Here are two from front, but I can redo them if you like.
http://img254.imageshack.us/img254/4...1811zj2.th.jpg
http://img254.imageshack.us/img254/1...1841ps1.th.jpg
I was told the ICs are not listed because they are done by different manu and wont have the same codes. :confused:
AFAIK the markings listed are correct. I checked and double checked them.
http://omgwtfbbq.ovh.org/files/8600gt_vmod1.jpg
What are the markings on this one?
That mysterious IC doesn't look like part of PWM anyway, it would be surrounded by caps and resistors.
Is that a Fatal1ty edition 8600GT?
That one is here:
http://img293.imageshack.us/img293/8251/cm1xo61kf9.jpg
The card is XFX 8600GT 512MB, DDR2. Not Fatal1ty edition, is lower end model.
^
"AT88SC" - Just another EEPROM.
As is "MEC25LV512" too.
I'm quite sure either of those APV7067Ns is the vGPU phase controller. As it happens the vGPU choke is the "1R0" in this pic and one of the APV7067Ns is right behind it on the backside...
Too bad no datasheet can be found using the partnumber available.
Good thing pin designation of phase controllers is usually standard... ;)
Heh heh yikes. How do I go about testing this?Quote:
Originally Posted by largon
Thanks for the help btw guys!
Ah, didn't notice other chips on the 2nd shot. That MEC25LV512 seems to be "3.0 Volt-only, Serial Flash Memory With 25 MHZ Spi Bus Interface", and APV7076 (or anything similar) does not figure in DigChip database. I am clueless.
Oh and FYI I couldnt tell 100% if it is APV7067N or APW7067N. I have 20-20 vision and a magnifying glass and I cant see that thing lol!
A good picture of APV7067N, the one between gpu and DVI out, would help us. Try making 2 pics, one directly from above and second at an angle, so that traces are more visible (damn black PCB!).
Ok, I will do that in a few hours when I get home from work! Will try and get a decent macro shot with flash so traces are lit up better.
Remember to use external lighting rather than the flash when shooting macro.
I'd say fourth pin on the bottom row is feedback, but imma noob so let's wait for largon to confirm :D
Dunno how I missed this yesterday but anyways, APW7067N (not APV7~) was used as the vGPU PWM controller on several 7900 serie cards...
xoqolatl is right, 4th pin is FB (it usually is). So just measure the resistance between FB and GND, multiply by 20, then solder and you're done.
edit:
Forgot to point you to the correct APW7067N (as there are two of them onboard) ->
This one is the moddable IC.
Ok so measure resistance between this pin and ground, multiply by 20 and use that size trimpot. That correct?
How about vgpu measure, any idea?
VGPU measure should be on the 1R0 coil, the lead closer to the GPU, but i'm not sure.
Second APW7067N would be for Vmem, solder point is the same, Vmem measure should be here:
http://omgwtfbbq.ovh.org/files/8600gt_vmod2.jpg
Sorry if I create any confusion, I'm trying to learn vmods myself :D
Eldonko,
Indeed.
[wrong]Another measuring point would infact be the FB pin as it called feedback pin for a reason. ;)
It is vGPU. [/wrong]
:)
xoqolatl,
Yup.
vGPU on that coil is the posterior leg/pad = right side = closer to "0" in "1R0".
Perfect, thanks alot guys. I will do the vgpu mod either tomorrow or thurs and post results and pics!
Hmm this is going to be a tough soldering job, those pins are soooo small.. :( Just went and bought a new smaller tip.
Resistance = 0.62k. Sp 0.62 x 20 = 12.4 kohm. Does than mean 20k or 10 trimpot? I guess 10k will inc voltage quicker and 20k slower?
Also what am I grounding to, pin 7? Or does it matter?
10kΩ should be fine.
edit:
Ground point doesn't matter.
Did the mod yesterday, 10k trimpot, used pin 7 as ground, and 1R0 as read. Works perfectly. :) Pics when my ISP at home gets fixed.
I think I learned some useful stuff here, let me know if this is correct for process as I would like to be able to figure out these mods on my own going forward.
1) so you find the right chip, pwm control.
2) read codes and look up datasheet
3) find fb pin and measure resistance to ground.
4) multiply resistance by 20 to find right trimpot.
5) do mod, yay you are done
Thanks again, much appreciated. The only thing that sucks is I can only get 2 hwbot points per bench since it seems I am the only one benching this gpu.. :cool:
That's pretty much how it goes.
:)
Looks good Zac ;).
Keep vmoding it...