GIGABYTE Radeon HD 7870 Windforce3 Voltage Mod?

[Bobnova]

Should be fine, it doesn't have to carry much in the way of juice.

 

[N0ble]

Sweet, just need to wait for the trimpots to turn up now.

In the mean time, i'm going to do my sense mods now, to check they work.

I will report back shortly

 

[N0ble]

Vsense soldered and working on card 1 now to do card 2.

I have also covered the solder points in Araldite epoxy resin to ensure they dont move.

 

[Bobnova]

Awesome.

I like to use hot glue, that way I can get it off if I want to eventually. On the other hand it doesn't always hold.

 

[N0ble]

I have managed to get the second card soldered but found it difficult to get the solder to actually come off the tip.

Even when attempting to tin the cable.

Im using a pin tip and lead-free solder
Sn 99.3%, Cu 0.7%

Its ok for these larger solders but i can see me having an issue soldering to the small cap when doing the vmod if i dont work something out.

Any tips for this?

 

[Bobnova]

See if you can find some 60/40 solder, that's lead (pb) and tin (Sn). Flux core is best, 0.022" (whatever that is in metic. Thin, in any case).
That's far easier to work with than the modern RoHS compliant stuff like you have.

 

[N0ble]

Is this stuff any better?

It's got silver content with a non corrosive flux?
So it says anyway.

http://www.maplin.co.uk/lead-free-silver-solder-34965

A lead-free alloy solder containing a non-corrosive flux
Improved conductivity and flow
Lower melting point


This solder is 4% silver, 95.5% tin and 0.5% copper. We recommend this solder for use with the iron-clad and nickel-clad bits supplied with our soldering irons. Solder is 1mm diameter and available in tubes (approximately 17g) and 100g rolls. The high silver content improves the conductivity of the solder and lowers the melting point, improving the flow.

 

[Bobnova]

Better. What you really want is lead if you can find it. It makes fantastic solder. Might be tricky to find in RoHSland though.

 

[TsunamiJuan]

liquid electrical tape works good to for holding that stuff inplace, also comes off well if you go to remove/move stuff.

I would definitely recommend using leaded solder for this stuff. Much lower melting temp makes it easier to work with. Some of the components are temp sensitive at the types of temperatures that lead free solder just starts to be come workable. Also it doesn't hurt to have some brush on or liquid clean free flux. You can use the stuff the requires cleaning afterwards but they go through a heat range that they become a contact inhibitor near the end of effetive heat range. Plus its a pain in the butt to clean off.

 

[N0ble]

The solder im using right now is horrible stuff, the tinning stuff i have makes a better solder lol!

I have a clean free flux pen, but it seems to be a little agressive when solder gets touched on the area i have put the flux on.
End up with scorch marks around.
I'm using a 15w iron.

I'm going to look to see if i can get lead solder form anywhere.

 

[TsunamiJuan]

Need a better spec sheet on that solder to really say. I don't see it showing the working temperatures for the solder.

 

[N0ble]

Ended up making a small ball of solder so it would actually attach!

 

[N0ble]

would this do the trick?

http://www.ebay.co.uk/itm/100g-Roll...Home_Garden_PowerTools_SM&hash=item5ae7134421

There is 25.4mm per inch so its 0.027"

 

[Bobnova]

That stuff should work great.

 

[N0ble]

Is this thickness of a floppy lead wire thick enough?

I have pulled the insulation back and its a multi strand wire, would'nt it be better to use a single strand wire?

 

[Bobnova]

I use 80pin PATA/IDE cable wire. Thinner than floppy/40pin IDE.

 

[N0ble]

i will use the floppy lead then, i think any thinner and i will not be able to see it with my eyes haha.

 

[TsunamiJuan]

yeah 60/40 should work great, its got a nice melting point of 190c instead of the 240-250c range of the ROHS stuff.

 

[N0ble]

Nice, thanks for the info.

So here we go... the two cards with vsense mod..

For some reason when having both cards plugged in at same time the second card will run at 1.1 volt until you put it under load in the OS and then its within 0.06 of a volt with the other card.... maybe this is what happens with the RIVE board....

Both cards function normal when run stand alone.

 

[Bobnova]

Power savings, AMD spent a lot of effort on making the cards draw as little as possible. I'm surprised card2 doesn't go lower than that actually.