How-to: Pencil mod your HD 3870!

DanishDevil · Mar 18, 2008

I tried to erase anything not on the resistor. Just cut the tip off an eraser and use the edge to clean up around there. I'd blow the dust off too.

And I thought I killed my card once. It took a full rubdown of alcohol to get it working again, so I think graphite was the killer, and I was God.

DanishDevil · Mar 18, 2008

DanishDevil said:
I tried to erase anything not on the resistor. Just cut the tip off an eraser and use the edge to clean up around there. I'd blow the dust off too.

And I thought I killed my card once. It took a full rubdown of alcohol to get it working again, so I think graphite was the killer, and I was God.

That'll do it.

Dr. Spankenstein · Mar 18, 2008

If you just shaded "around" the resistor to get that reading, you should be o.k..

Just make absolutely sure you removed the excess dust from everywhere else.

Boot up, measure volts (you did change your DMM back to "Vm" @ 20, right!), and watch those temps!

freaksavior · Mar 18, 2008

1.097

time to stick it back in

1.39v on start up.

Dr. Spankenstein · Mar 18, 2008

Lookin' good. Spin up those fans!

freaksavior · Mar 18, 2008

one down.

both have a vcore of 1.39 and 1.36

freaksavior · Mar 18, 2008

Ok so i cant hit 860 core or even 1260 memory, 3dmark fails.

so yeah...i don't know. do i need to ad more?

DanishDevil · Mar 18, 2008

It might be that clock limiting bios. And yes, you could need to add more. What are your temps like?

freaksavior · Mar 18, 2008

46 for his 38 for diamond thats idle

i flashed my bios with the newer one and the his is a newer revesion so it should have the new bios.

DanishDevil · Mar 18, 2008

Yeah the HIS doesn't have the lock.

Let's see...it took me...on my HIS card, about 1.43V to get much above what stock volts would give me, and I got from about 830 to 870. Any more volts was unstable.

Run FurMark in Stability mode for 30 mins to see your load clocks.

freaksavior · Mar 18, 2008

oh, well when i get home, more volts

freaksavior · Mar 18, 2008

whats is the safest vcore for the 3870?

DanishDevil · Mar 18, 2008

I wouldn't go over 1.55V if you can even get there. Esp. on air.

MagnusLL · Mar 19, 2008

Hi. I own a 3870 Powercolor PCS (which uses a non reference board), and I'm interested in modding it to add a little more voltage.

I've read the thread and found back at page 17 the images reporting the pencil mod spot (though it's different from the one reported on xtremeforums for this same model, I guess both are valid) and the vcore measuring points (which I just tested and they seem to work, though my multimeter for some reason doesn't feel like stabilizing itself).

A couple quick questions: does anyone know the solder point should I want to go the trimmer route? What about memory modding and measurements?

Thanks.

croni-x · Mar 19, 2008

Hey guys, i want to do a pencil mod with my PowerColor HD3850, too. But i've not found any picture of my layout so i took a photo of it, and hope you can help me.

ghost101 · Mar 19, 2008

croni-x said:
Hey guys, i want to do a pencil mod with my PowerColor HD3850, too. But i've not found any picture of my layout so i took a photo of it, and hope you can help me.

I think. Its a shame there isnt a resistor there though.

croni-x · Mar 19, 2008

Can i measure the resistance here ? And i just have to connect the two pins via pencil and measure up the resistance until i got a good value ?

DanishDevil · Mar 19, 2008

Don't think so. Your card wasn't designed to bridge your core voltage between those two points. You might fry your card.

Try the second pencil mod...it's somewhere deep in the pages here. It involves bridging two points like that, but elsewhere. I would wait until RandomMurderer had a look, though.

Random Murderer · Mar 19, 2008

ghost101 said:
I think. Its a shame there isnt a resistor there though.

yea, if there was a resistor there, it would work. i've notice a lot of the newer 38x0 cards that don't have an r1222... surely this is because they caught wind of the pencil mods?

croni-x · Mar 19, 2008

That one should work ? Dont want to grill my card

DanishDevil · Mar 19, 2008

Not sure. It could just be that they're going a different route with PCBs to improve on the reference design. Maybe it is. Maybe we have moles in our forums that are feeding out every post to these companies right now :wtf:

Edit: If RandomMurderer posted it, then it should work. He knows his stuff.

croni-x · Mar 19, 2008

Okay thanks. I'm carefull because i'm doing such a mod my first time, so i want to ensure all should be right

So i just draw a line between the both ends of the resistor and measure until i got the right resistance. Should i draw the line round the resistor or on it ?

DanishDevil · Mar 19, 2008

On it. You don't want any extra pencil lead anywhere but on the resistor. After you're done shading, blow the extra graphite off, and if you like, use an eraser VERY GENTLY to remove excess lead from around the resistor. It's tough, since the little buggers are so small, but you'll get the hang of it. Start slow, and don't get flustered.

Cold Storm · Mar 20, 2008

There is no telling who has seen this thread, or what has been talked about because of this thread. Its been seen, we can tell by the 28,713 views that there is a few people other then us who have seen it. Just don't know if the cards now have been done up because of it. Just like any other mod, its going to be found, and done if thought about. Just wish it wasn't a pain in the ass mod! lol.. But is good mod at that!

DanishDevil · Mar 20, 2008

Well, I haven't done the soldering trimpot version, but I personally think the pencilmod isn't hard. I think it's fun! Like lapping a heatsink

Even if I got like 40MHz out of it.

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System Name	Big Devil
Processor	Intel Core i5-2500K
Motherboard	ECS P67H2-A2
Cooling	XSPC Rasa \| Black Ice GT Stealth 240 \| XSPC X2O 750 \| 2x ACF12PWM \| PrimoChill White 7/16"
Memory	2x4GB Corsair Vengeance LP Arctic White 1600MHz CL9
Video Card(s)	EVGA GTX 780 ACX SC
Storage	Intel 520 Series 180GB + WD 1TB Blue
Display(s)	HP ZR30W 30" 2650x1600 IPS
Case	Corsair 600T SE
Audio Device(s)	Xonar Essence STX \| Sennheisser PC350 "Hero" Modded \| Corsair SP2500
Power Supply	ABS SL 1050W (Enermax Revolution Rebadge)
Software	Windows 8.1 x64 Pro w/ Media Center
Benchmark Scores	Ducky Year of the Snake w/ Cherry MX Browns & Year of the Tiger PBT Keycaps \| Razer Deathadder Black

Processor	Intel C2D E8500 @ 4.25GHz (1.36V)
Motherboard	Gigabyte GA-X38-DQ6
Cooling	(Temporary) Tuniq Tower 120
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Video Card(s)	HIS HD3870 CF Volt modded
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Processor	Intel C2D E8500 @ 4.25GHz (1.36V)
Motherboard	Gigabyte GA-X38-DQ6
Cooling	(Temporary) Tuniq Tower 120
Memory	2GB Transcend aXeram 1200+
Video Card(s)	HIS HD3870 CF Volt modded
Storage	3 Seagate 320Gb Barracuda in an Intel Matrix Raid array
Display(s)	Sony GDM-FW900 24" Widescreen CRT (a.k.a "The Shiznotch")
Case	Ultra Aluminus Full Tower
Audio Device(s)	onboard Intel HD audio
Power Supply	PC Power & Cooling Silencer 750
Software	XP MCE + Vista (HP) dual-boot

How-to: Pencil mod your HD 3870!

DanishDevil

DanishDevil

Dr. Spankenstein

freaksavior

To infinity ... and beyond!

Dr. Spankenstein

freaksavior

To infinity ... and beyond!

freaksavior

To infinity ... and beyond!

DanishDevil

freaksavior

To infinity ... and beyond!

DanishDevil

freaksavior

To infinity ... and beyond!

freaksavior

To infinity ... and beyond!

DanishDevil

MagnusLL

New Member

croni-x

New Member

ghost101

croni-x

New Member

DanishDevil

Random Murderer

The Anti-Midas

croni-x

New Member

DanishDevil

croni-x

New Member

DanishDevil

Cold Storm

Battosai

DanishDevil

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