Voltage drop on VPU...

[dpa]

Hey,

I have a PowerColor 9800Pro card. Im running a VapoChill XE on it, BUT I have a problem. When I pump the voltage and mhz UP, (510+ 2v+) the voltage drop down to 1.92-1.96 under heavy load.. Nature crashes at the same place every time..!

Vagp = 1.8v (tried auto, 1.6 and 1.7 also..)

Is the vreg on this card just ":banana::banana::banana::banana:ed"?

dpa

Norway

[dpa]

I know, the card really sucks. i have good contact to core I think, used your "idea"..

http://www.home.no/dpa/vapoxe006.JPG

http://www.home.no/dpa/vapoxe005.JPG

my 5v rail is at 5.4v and 12v rail is at 12.6v..

i hate this card..!!

EDIT: i dont have -40 evap temp.. -29-30 at idle.

[asw7576]

You need to add 5V booster cable as seen in the pic. I measured the voltage at diode input = 5.3V and it drop to 5.0V during 3dmark benchmarking.

You don't need the extra capacitor. I'm just crazy..... :D :D

http://mywebpage.netscape.com/asw7576xx/9800_4.jpg

[dpa]

just solder a wire between those 2 spots?

is that "safe"?

[asw7576]

of course...... before doing any mod, you can measure the voltage on diode input. ( you know how a diode works right?? ). This is my card @ idle: the diode's input side = 5.3V and diode's output side = 3.9V

Now...... I test under 3dmark benchmark, the diode's input will drop to 5.05V to 5.15V during the test. And so thus on the output side.... it will be lower voltage too. I think this diode is responsible for VPU.

What you want to do is to give a 5V booster cable so the diode's input won't drop so much under loads.

I use single copper wire from CAT5 cable. Follow the green line.

http://mywebpage.netscape.com/asw7576xx/9800_booster.JPG

[STEvil]

That booster cable is a good idea.. :D

[dpa]

idle at my powercolor card:

input : 5.15v
output : 3.26v....

your output is alot higher than mine!

[saaya]

nice! i assume this works on 9500s as well? :D

[asw7576]

Originally posted by dpa
idle at my powercolor card:

input : 5.15v
output : 3.26v....

your output is alot higher than mine!


no.... let take the genuine reading from yours: 3.26V.

I forget the output side from mine. It should be the same as yours.

[Hell-Fire]

Interesting idea.

I used the same "idea" on my old A7N8X board. Connected the legs across 2 mosfets.

[G H Z]

Originally posted by saaya
nice! i assume this works on 9500s as well? :D

Lets find out shall we.

Just need to find the correct spot for the jumper wire on the 95/97 pcb.

Any idea's asw?

Here's the best pic I could find of the same area on a 95/97
http://thecrucible.ca/images/vgpu.jpg

This looks to be an earlier revision

[asw7576]

That SC1175CSW is for VGPU mod, but I don't know the correct VR value for ATI 9700 or 9500 series to start.

You quoted 10K ohm to start? I think it's okay since R300 core is same as R350 = 1.7V default VCORE.

But the pins to solder is correct. Look here..... SC1175CSW on 9800 PRO:

http://mywebpage.netscape.com/asw7576cc/vcore.jpeg

http://mywebpage.netscape.com/asw7576zz/9800P_vgpu.jpg

[saaya]

hmmm

connecting the legs of the mosfets that produce the same voltage is a good idear to prevent fluctuations on mobos and videocards... i wonder why none of the manufacturers did that already?

[Iolao]

Originally posted by asw7576
That SC1175CSW is for VGPU mod, but I don't know the correct VR value for ATI 9700 or 9500 series to start.

You quoted 10K ohm to start? I think it's okay since R300 core is same as R350 = 1.7V default VCORE.

But the pins to solder is correct. Look here..... SC1175CSW on 9800 PRO:


Question is: where is diode on 95/9700 pcb? I did try myself to connect 5v line but I cannot seem to be able to solder to those little pins (the ones you have linked the cap for example).

[Kamerat]

Originally posted by dpa
just solder a wire between those 2 spots?

is that "safe"?
Safe? When started you care about that? ;)

[STEvil]

http://mywebpage.netscape.com/asw7576zz/9800P_vgpu.jpg

Far left of that pic, I think?

[G H Z]

Originally posted by asw7576
That SC1175CSW is for VGPU mod, but I don't know the correct VR value for ATI 9700 or 9500 series to start.

You quoted 10K ohm to start? I think it's okay since R300 core is same as R350 = 1.7V default VCORE.

But the pins to solder is correct. Look here..... SC1175CSW on 9800 PRO:


I wasn't looking for the location of the Vgpu mod.

What I was asking is if you know where 5v jumper wire would be used for a 95/97 pcb as I get the same voltage drop. But I see no mosfet on the 95/97 pcb near the location your pointed out for the 9800.

STevil the last pic again is the 9800...........

[G H Z]

Here's another view
http://ministryofoverclocking.net/pics/30746.jpg

[STEvil]

The large solder pads to the right could be where the diode is supposed to be... maybe it is under the plate on the 95/9700..?

EDIT - Im bright.. just realized that is a pic from under the plate.. - /EDIT

lemme open my case...

Right close to the floppy connector could be it..

I dont have enough light to look properly right now and poke with my DMM... :/

[STEvil]

Bump..

Anyone had a better look at their 9700 yet?

[STEvil]

EDIT

See below! :eek: :slobber: :eek: :D

[G H Z]

Cool,

Thanks StEvil but I wish I could see that clearly. Wanna try it with that last pic I posted?

Did you measure a v drop happening there? Ah, maybe not in that pic??

[STEvil]

Better pic.. this camera is picky for distances and light conditions... :rolleyes:


Its the one in the hole nearest the edge of the card under the plate...

Disclaimer: Im only giving measurement locations!!!!!!! :eek:

EDIT

I measured load/idle volts from the backside of the aux connector on the card, and there were no voltage drops... same with off the capacitor near the plate.

I was only using rthdribl, though, so it wasnt enough load to induce a drop I dont think...

An extra cap may clear up the voltage drop at the cap anyways, and the booster line will allow for a more maintained charge...