X800XL AIW Need VGPU Mod!!

[G H Z]

A friend over @ OC Forums has this card and is searching for the vgpu mod.





Thanks for any help

[d]g[ts]

Thanks for posting G H Z I'm the guy that owns this, and realy cant figure much on it since it's so Different from other XT's Anyways any help would be greatly appreciated, and more detailed pics can be had if required. THanks in advance D]g[ts

[persivore]

Can you check if pin 13 on the ISL6539 is connected to ground (resistance between pin 13 and ground should be very close to 0ohms if it is). That should make it clear if the ISL6539 is being used as a Vgpu regulator, or if it is the Vmem regulator.
It looks like there might be other voltage regulators to the left of the picture, which I suspect will be for Vdd (Vmem) and Vddq, but they could be used for the Vgpu if the ISL6539 is being used for Vmem.

[d]g[ts]

I checked that point, and it was infact grounded. also included pic of that pin highlighted.

[persivore]

Ok, thanks
It looks like the ISL6539 is controlling the Vgpu, and possibly another voltage as well.
Can you try to find a Vgpu read point (it will probably be a capacitor leg, which should read between 1.3-1.4v). Can you then check if the Vgpu read point is connected to either pin 4 or pin 25 on the ISL6539. That should confirm that the ISL6539 is the Vgpu regulator, and which half of the regulator is being used for the GPU regulator.

[d]g[ts]

Ok, thanks
It looks like the ISL6539 is controlling the Vgpu, and possibly another voltage as well.
Can you try to find a Vgpu read point (it will probably be a capacitor leg, which should read between 1.3-1.4v). Can you then check if the Vgpu read point is connected to either pin 4 or pin 25 on the ISL6539. That should confirm that the ISL6539 is the Vgpu regulator, and which half of the regulator is being used for the GPU regulator.

looking at card, and capsI would believe you are refering to the larger type capacitors that have pins through the PCB. sorta like on the 9800 pro where a line of 3 caps is present, and VGPU read is is a pin on back side of PCB from one of those caps. But on this board there is a line of 3 caps, but they are surface mount, and right below the ISL6539. am I looking in proper direction, or should be looking for different SMD type caps?

[persivore]

Try checking around on the line of 3 caps below the ISL6539. There might be other caps around the regulator which read Vgpu as well tho. I'm not exactly sure which capacitor(s) will read Vgpu, so you might need to probe around until you find one

[d]g[ts]

did some poking around on card , but to no avail. not able to get readings from points 4, or 25 on chip, as they are too small to poke at with card on, and caps are suface mounted on front and unable to reach all points while card is on.

[G H Z]

d]g[ts,

Can you get a pic of the backside that is a least 1000 pixels wide? Maybe we can help find a likely read point or two. For measuring pin 4 & 25 if your probe is large try using a needle or small wire to bridge the probe so you can verify the readings, or maybe you can follow the traces to read at another spot on the card.

If your running in a case it would help if you had it out on a table so you could get to the card more easily

[persivore]

Ideally, I needed the voltage at pins 4 and 25, but I thought that they would be too small to measure with the card on. I suggested that you find a Vgpu read point and find the resistance between the read point and pins 4 and 25 as a 'workaround' because you don't need power on the card when measuring resistance.
I could make a guess as to which half of the regulator is controlling Vgpu, but I'm a bit reluctant to do so, when I could be 99% sure that I've got the right point to mod if I can get the appropriate readings.

There looks like there is a MOSFET below the voltage regulator - can you try to get the voltages at each of the pins instead. I'm not sure if it will be used for the Vgpu regulator, but its worth a try.
A close up pic of the regulator and surrounding area might help as well, to try to find an alternative point to solder to, so that you don't have to solder directly to the voltage regulator.

[d]g[ts]

using a sewing needle i got 1.45V on pin 4 and 1.42 on pin 25
I have 3 meters here, and all seem a tad low on batteries. but was able to get those 2 reading. the tiny mossfets to left of chip seem to be regulating the 12v down to 2 v between the two of three neard the chip.

Better pics I'm finding hard to get with my crappy cam, seeing the best so far was the pic in post4

[persivore]

From that, I think that the second half of the regulator is controlling the Vgpu. Can you check the resistance between pin 25 and pin 19, and pin 19 and ground.

[d]g[ts]

From that, I think that the second half of the regulator is controlling the Vgpu. Can you check the resistance between pin 25 and pin 19, and pin 19 and ground.

from what i've just read. 25-19 = 14.11kOHMS and between 19 and ground = 14.22K ohms. gonna have to rip it from case this evening to find VGPU measure. dont have much time, but will need it to proceed i'm guessing

[zxlr8]

Would this mod work for the x800xt aiw. I am in need of a volt mod for it....

[d]g[ts]

the board pictured above is an XT, and not an XL. Unfortunatly I am no further on this. Now i was advised that pin 10, or 19 on the IC via a VR (100K) to ground would work, however neither worked for me as dropping below the resistance thats already there (14.22K OHMS at both pins) would result in a no video initialization issue. Since then, I have done rather much nothing with it.

[zxlr8]

Well, where do we go next with this? I am about ready to pull my hair out. I really would like to see more performance out of this thing. ANybody?

[d]g[ts]

I would say try to get better pic than what i have, to see if anyone else can make somthing out. Otherwise I'm stumped at this point.

[zxlr8]

Anybody?????? :^)

[persivore]

the board pictured above is an XT, and not an XL. Unfortunatly I am no further on this. Now i was advised that pin 10, or 19 on the IC via a VR (100K) to ground would work, however neither worked for me as dropping below the resistance thats already there (14.22K OHMS at both pins) would result in a no video initialization issue. Since then, I have done rather much nothing with it.

Can you try doing the same ting, but with a 200 or 500k variable resistor. 100k might have been too small, and could have been forcing the card into OCP/OVP. Also, check the voltage that is being given out when you do the mod to check if it increases, or if it falls to 0v (which could indicate OVP/OCP)

[zxlr8]

bump...

[CaTalyst.X]

That ISL6539 could control VDDR...but im betting it just controls vGpu...Ill take a look a bit more.

Also what is written on the IC Circled.

-CaT

[zxlr8]

Thanks for your help, Cat. I will be watching this thread intently. I wish I knew more about this kind of crap.

[CaTalyst.X]

lol no problem, ISL6559CB is definately the vgpu controller and im almost positive that IC i circled controls vddr. Hopefully itis the ISL6522CB.


-CaT

[zxlr8]

So what would the mod look like?

[CaTalyst.X]

Any info on that chip I circled..?

-CaT