Time to put my eVga 5700LE through the torture tials. Vmem mod please?

[Reznik Akime]

I made me some hunkin ass ramsinks for this card with a heatsink that came with a dell that had a 2.4 celeron in it. I hacked it up with a saw and sanded it down some with a belt sander and plan on using some arctic alumina adhesive to plant these suckers on..

But! It comes down to this. I dont yet want to put them on because I can only get about 500mhz out of the ram. Any higher and it starts to artifact. The GPU though can overclock damned good, from 250 to 450 on just the measely little stock cooling it has. Im sure if I could get some better cooling on it I could easily break 500.

Back on track.. I want to hold putting those sinks on to see if I need to do anything too it to save from prying that thermal epoxy off.

Again, this is for a eVga 5700LE, the previous tutorials will -not- work on this one. Its got 256 mb of ram.

[persivore]

Can you post some pictures of the back of the card please.

[Reznik Akime]

Sure thing. Infact I think I have some somewhere on this computer already. If not, gimme a bit to post em.

[Reznik Akime]

Here it is. Yeah, I know its rather crappy..

Thats the right side of the card when yer lookin at its back side. The left side was completely sparce of any chips cept for a few ceramic caps and those itty bitty three pin black thingies. If you need the digits of any chips, lemme know.

[persivore]

Can you tell me what is written on all 3 of the chips in the pic please.

[Reznik Akime]

Yep. Gimme about 10 min.

[Reznik Akime]

Going from the top chip, then the one on the left, then the one under that.

RT9205
CS5M50E


P15C
3257Q
B704


Texas Instruments made this one:
39AY4DK
ACT08

On the ACT08, it may be ACTD8, I cant really make it out.

[persivore]

The RT9205 is a regulator, but I don't know if its being used for the Vgpu or the Vmem (its probably for the Vgpu imo). The other chips don't look like they are regulators. Are there any other chips on the front of the card?

[Reznik Akime]

Only three, but I know two of them (The ones under the thing labeled 1R0) are Mosfets from International Rectifier. I had to replace the left one when I tried making my own volt mod using a guide on the OC forums and blew it. Sizzled and boiled up the plastic casing.

Works now since I replaced it, but I decided to seek higher help for a second time round. >>;

[persivore]

Can you try to find a point which reads the Vmem voltage (about 2.5-2.8v), and find the resistance between the Vmem read point, and the pin I have marked (pin 6/feedback). I can't see which pin is pin 1 from the picture, but you can probably work it out from this picture

[Reznik Akime]

I assume this is it. I got it off one of the caps that was under the ram on the front of the card. It reads 2.54 so it sounds about right. Gimme a sec and ill check the resistance.

[Reznik Akime]

Got the resistance. From the measure point and pin 6 its .70

[persivore]

I think that the Vmem mod should be to connect a 20k variable resistor between pin 6 on the RT9205 and ground. Check both the Vgpu and Vmem before you start increasing the voltage to check that it is the Vmem which is being increased because I'm not 100% sure that the RT9205 is for the Vmem.

[Reznik Akime]

I only have 10k resistors..I dont think radioshack carrys em..

[persivore]

Put 2 10k variable resistors in series.

[Reznik Akime]

How would I do that? I jumbled the idea in my head just now.. But I wasnt sure how or if you could do it.

[Reznik Akime]

Ack.. I just came to realize something.. Those caps next to the memory keep the heatsink from mounting properly on the ram. Its got like a very, very tiny gap hardly seen, but it also grounds off the caps to one another.. What to do? =/

[persivore]

Connect them like this :)

[Reznik Akime]

Ohh.. I see now.. That makes sense.

But what about my most recent problem? It was hell cutting this aluminum heatsink apart with a hacksaw.. Is there an eaiser and more precise way of cutting it to make it fit without touching the caps?

[persivore]

Sorry, I missed your last post. You could try cutting the sinks using a 'dremel' or similar tool.

[Reznik Akime]

I have a drimmel.. Ill prolly try that later.. Maybe..

[Reznik Akime]

Oh! What are the possibilities of adding a cap to this as well? How would I go about doing that? Just find the Vmem.. Thing.. Cant remember what its called.. and a ground point and connect the cap between em?

[Reznik Akime]

I found the measure point for the vram.. although the daisy chain I made with the resistors only yeilds a .68 as a maximum resistance. Both pots are turned up to max. I realize thats .02 less than what it was originally.. But I dunno the formula to calculate the voltages given at such a rating.

-edit-

I just plugged it in and prodded V1 and it now gives a reading of 2.65. I need to get the spec sheets on this ram to see how high a voltage it can go before they kill off. I was able to get an extra 30mhz out of the ram, its now clocked to 530mhz when I couldnt get past 500 earlier.

-Yet another edit-

I got it to max out at 545 on 2.70. Refuses to go any higher.. even with more voltages. What could be done to get higher? Still have yet to do any benches on it simply cause I dont have any benching software yet.

[persivore]

Sorry, I missed your last posts...damned email filters!

Oh! What are the possibilities of adding a cap to this as well? How would I go about doing that? Just find the Vmem.. Thing.. Cant remember what its called.. and a ground point and connect the cap between em?
That sounds ok, Just use low ESR capacitors. I've heard of cap mods killing some graphics tho, so try not to add too much capacitance (or were you talking about adding a cap to the voltage divider? If you were, the reference voltage for the regulator is generated inside the regulator, so you shouldn't need one)

I found the measure point for the vram.. although the daisy chain I made with the resistors only yeilds a .68 as a maximum resistance. Both pots are turned up to max. I realize thats .02 less than what it was originally.. But I dunno the formula to calculate the voltages given at such a rating.

-edit-

I just plugged it in and prodded V1 and it now gives a reading of 2.65. I need to get the spec sheets on this ram to see how high a voltage it can go before they kill off. I was able to get an extra 30mhz out of the ram, its now clocked to 530mhz when I couldnt get past 500 earlier.

-Yet another edit-

I got it to max out at 545 on 2.70. Refuses to go any higher.. even with more voltages. What could be done to get higher? Still have yet to do any benches on it simply cause I dont have any benching software yet.
That resistance decrease sounds ok for the value of varaible resistor(s) you used.
It should be safe taking the mem voltage to about 2.8v. The problem with the RAM maxing could be caused by Vtt/Vref not following.

[Reznik Akime]

Oh yeah. I remember reading that some things have regulatory settings upon them as a failsafe and they sometimes need to be averted by soldering a direct line that bypasses the chip.. I dunno how to do that. o_o

And I tried poking around to figure out where to put the cap, but if its not gonna help much I wont bother with it.

Oh, a bit late, but thanks for the help, man.

[Reznik Akime]

Ive looked around.. but I cant find anything on changing the Vtt/Vref. I know ive seen something on it before.. But.. I cant remember where. ><

[persivore]

I can't see any regulator on the card which might be the Vtt/Vref regulator but there might be regulators on the front of the card.

[Reznik Akime]

That one section of the front I shown you was the only place that had any kind of chips that could possibly be that.. Hmm..

[persivore]

The Vtt/Vref regulator might be formed from discrete components then, so you would have to find the regulators reference voltage and change it (but that could be quite hard)

[Reznik Akime]

What would it require me to do? I found the hole thing that reads off the Ram's voltage, but I think thats not what im lookin fer, is it? If I knew about what I was lookin for or how to get it, I could prolly go from there.

[persivore]

If your looking for Vtt, then it should read 1/2 of the Vmem. I think Vref should also be 1/2 of Vdimm, but I'm not sure.

[Reznik Akime]

Ima check that out in a bit here when I find my damned Multimeter.. I seem to have misplaced it..

[Reznik Akime]

I can find things reading 1.25, Half of the stock voltage but I cant find any reading 1.35 anywhere other than the silver points behind the ram.. Hmm..

[Reznik Akime]

Why.. Why me.. Why does everything I try to do seem to kill something? God im so... Ugh..

I was prodding around at the front the card to find the Vtt.. I look up and everything is fine. Screen is still on. I then look down, prod near the memory, look back up and black screen. I restart.. Now I get artifacting so bad I cant make it out.. I take off the mod.. Still artifacts.

Why does this :banana::banana::banana::banana: happen to me? :brick:

Every time I try and be careful I screw something up. That was my last decent card. I sold my other satisfied that I wouldnt mess up.. Now im stuck with an ATI card thats from 1998 or a voodoo3.

Is there any chance of fixing it..? I dont have the money to replace it now and I was getting back into UT2k4.. ><

[SikaRippa]

Sorry about bad lucky you had :(

--

Is it possible you made short while probing ?

Do you still have correct (the same) voltages for VDD & VTT ? If the values are the same , the power supply part should be OK ! But .. depending where short occured either memory or GPU might have suffered.