PCX5750 vmods needed

[CrazyXP1700]

hey guys... im looking to get my graphics card v-modded so i can get #1 on orb again... what all info do you guys need...

http://www.geocities.com/crazyxp1700/IM000530.JPG

http://img.photobucket.com/albums/v320/CrazyXP1700/Computer%20Crap/IM000533.jpg

i'll list all of the IC's in the morning... but some you may be able to make out, who knows... let me know what is needed to move on :toast:

[persivore]

Can you tell me what is written on the chips I have circled please.

[CrazyXP1700]

http://img.photobucket.com/albums/v320/CrazyXP1700/Computer%20Crap/ICs.jpg

i really couldn't make out a few of the IC's... i cant find my magnifying glass... so i tried to get a better pic, so you could possibly guess if i am wrong

[persivore]

Those chips look like MOSFETs, the GFX BIOS and an analogue switch :(. What is the chip on the front of the card, near the bottom?

[Bennah]

vgpu and vmem mods would be good to me too ;)

I have no idea how it could be vmodded tbh... but I hope someone out there knows how to do it :D

[CrazyXP1700]

you know i'll let ya know how to do it bennah :D

http://img.photobucket.com/albums/v320/CrazyXP1700/front.jpg

well those are all the IC's on the front...
thee was also one more IC in the back, that you didn't ask me to list... it was
APL1117 AFCOJ, probably is nothing though

there is also 43AVRXK, ACT08

[persivore]

The ISL6534 is the voltage regulator. It contains 3 regulators, so is probably controling Vgpu, Vmem and probably Vtt.
Can you check the resistance between each of the pins I have marked and ground, and each of the pins and a Vgpu read point/Vmem read point/Vtt read point. You should be able to find the read points by checking the voltages at inductors/capacitors/MOSFET pins.

Picture (http://tom.drunken-student.co.uk/mods/IM000533.jpeg)

[CrazyXP1700]

Pin 1 reads 0.54
Pin 4 reads 1.92
Pin 12 reads 0.75

[persivore]

Is that between the pin and ground?

[CrazyXP1700]

yes...

i had the card pulled out of the system... do you think that had affected it any?
where would the readpoints be for each one? or should i start "feeling around caps and writing the volts down

[CrazyXP1700]

http://img.photobucket.com/albums/v320/CrazyXP1700/vs.jpg

[persivore]

I think the Vgpu mod should be to connect a 20k variable resistor between pin 1 and ground.
Vmem should be to connect a 50k variable resistor between pin 4 and ground.
I'm not certain that fb1 (pin 1) is for Vgpu and fb2(pin 4) is for Vmem, so check both the Vgpu and Vmem whilst you increase the voltage.
The Vmem read point will be the point reading 2.53v, and the Vgpu will be the 1.33v point.
Vtt should be modded using pin 12, but I don't know if it will be needed.
Also, do the pins on the chip look big enough to easily solder to? If they are too small to solder to, can you post a close-up shot of the voltage regulator to try to find an alternative solder point please.

[CrazyXP1700]

i was just talking to my friend about that...
im confident i could solder on them, the only one that would be a little tricky would be pin 4... im sure i could still pull it off...
but ofcourse an alternative mod point would always help

http://img.photobucket.com/albums/v320/CrazyXP1700/Computer%20Crap/closeup.jpg

sorry about the quality... my camera sucks

[persivore]

Can you check if the points I've marked look like they are connected on the card.

[CrazyXP1700]

just a question... can i set a 50k vr to 20k and use it on the other point?

i have 2 50k vr's left over

[persivore]

It should be ok using a 50k, but the voltage adjustment might not be as exact.

[CrazyXP1700]

sounds good... thanks again bro :toast:

[Bennah]

ah nice work guys worknig out the mods... now go and try them out crazy and report back ;)

[CrazyXP1700]

hmm... i adjust the trimmer for the vram and it messes up card and puts it into powersaving mode... the ram voltage drops to 0.00v so i think im on the wrong point

the other points you listed didn't show the right resistance, so i put the mod on another point with the same resistance... but it's not working so i may just go right onto the IC, i should be able to get it on there

i also knocked a couple resistors off of the card, i forgot to clean the tip... and i got solder on 2 resistors... i still have them here on my desk incase i need them back on... but so far it appears they were not needed (unless they are for the v-ram, but its alot closer to the v-gpu) but it appears to not have affected the card at all... i think i got lucky

i am crazy... im doing this with a 140/100W soldering iron lol :slap:
really shouldn't be doing it with this...

v-gpu is working though :woot:

[persivore]

Good to see that you have the Vgpu working.
From your picture it looked like the points I marked might have been connected, but I might have been wrong. If you need an alternative solder point for the Vmem, measure the resistance between the point on the chip, and other SMD solder points on the card. If you find a point with 0 ohms (or close to zero, within about 1 ohm) the points should be connected and you can use the point as an alternative solder point.

[CrazyXP1700]

well i've got a new card now...
im still trying to figure out vmem...
what are the chances that it is off of pin 12... FB3...

[persivore]

well i've got a new card now...
im still trying to figure out vmem...
what are the chances that it is off of pin 12... FB3...
Vmem could be supplied by FB3. If you want to mod the voltage controled by FB3, connect a 20k VR between pin 12 (FB3) and ground.

[ALT-F13]

Hey, CrazyXP1700, just to keep you busy - I have a 18500+ back-up score on unmodded setup - too lazy to publish it now :) Gonna try hit 19k today with Vgpu modded :)

[CrazyXP1700]

Pin 12 (FB3) does control memory voltage :D

[ALT-F13]

Well, sorry for disturbance but looks like the race is over: http://xtremesystems.org/forums/showthread.php?p=983039

20002 (http://service.futuremark.com/compare?2k1=8668949)

[CrazyXP1700]

very nice... congrats

still what kind of competition is it if i dont try and beat that score :p:
even though that CPU you got is a beast... kinda unfair compared to an aircooled venice

[SikaRippa]

Hi,

I wonder you still trying to make a Vmem mod ? I have been investigating GF6800(le)-cards, which utilizes the same regulator chip ISL6534. In the case of the 6800-card I found a very easy way to mod Vmem, take a look this figure:

http://img216.imageshack.us/img216/4646/vmemmod16ir.th.jpg (http://img216.imageshack.us/my.php?image=vmemmod16ir.jpg)

The idea behind the mod is little bit different that presented in this thread previously: Changing the VREF-voltage rather that FB2 voltage. In the case of 6800-card that was too easy since REFIN and REFOUT pins were test points i.e. one can stick a resistor to those holes to get Vmem modified !!

--

It would be good starting point to:

- Check voltages of the test points in your card (I saw at least a few), and try tho identify for WHAT points they are i.e. Vmem, REFIN etc.
- Check whether 'REFIN' and 'REFOUT' are more easy to solder (pins 5 & 6)

[SikaRippa]

Sorry, double post.

[ALT-F13]

CrazyXP1700

Thanks and good luck with your results!!!