kingpincooling.com

Go Back   kingpincooling.com > Overclocking & Modding > TiN's Dungeon

TiN's Dungeon The mad engineer's home at KPC.

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 02-13-2011, 11:06 AM
TiN's Avatar
TiN TiN is offline
Volt-Nut :)
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,458
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Post [Zombie] Conversion your dead 2900XT into useful beast.

I see nobody wants to learn hard how to create their own zombie-creatures. Most of guys, to my disappointment, just soldering some wires, cutting cards, and smoking the results. Without trying to learn how step-down DC-DC converter works and controlled. So this time I will leave my pink dreams about worldwide knowledge alone, and post just simple "Do that step-by-step and you are done"

And I don't like radeon cards, so I will do evil things with it

Things needed: 2900 XT/Pro reference design card.
Tools: High-power solder iron (60 to 100W), saw, good to have some sanding tools, multimeter, usual ATX power supply for checks, some wires
Components needed: -TBD-
Time frame: 1 hour
Complexity: Easy



STEP 1

Welcome one of most complex PCB designs in gaming videocards market. Radeon 2900XT PCB with 512-bit memory bus, high-end R600 GPU and state-of-art Volterra VRM. This is what we zombienize today.



This exact patient have crippled GPU, lacks of passives, and memory chips, but fully functional power curcuitry. Perfect candidate for our task.

So for first step - get this card, with working VRM. You can check VRM easily by installing videocard into PC and checking if GPU and memory voltages are present and okay. No more checks needed right now. If voltages are ok - your card is able to be zombie.

Closer look on VRM side:



Two Volterra VT1165MF chips control seven VT1195SF power devices. There is also standalone Volterra VT233TF VRM, for memory I/O's. It's CSP square chip on left upper corner. VRM takes it's power from 8 pin minifit JR connector and 6-pin one.

STEP 2

Now take your favourite saw and do little dirty work.



Cut VRM from videocard, just straight next to memory chips. Do not inhale dust, it is not good for health. Clean up mess after youself.



So you should get this. Take care not to damage components on VRM side.

STEP 3

Now it's needed to finecut edge of cut, to prevent any interlayer metal shorts. If you skip this step - you will have flames and smoke of shorted curcuits, be sure.

This what I saw just after cut.



Then I took handmill tool with hardened edge cutter and milled edge a bit on medium RPMs.



After minute or two milling sides I get acceptable results



PCB cut should be just like this, without interlayer shorts.

You can clearly see complexity of PCB of this high-end videocard. It have two core copper planes and five signal layers each side from them! Total twelve layer of copper. For comparsion, 8800GTX have twice less. Also this PCB feature buried microvias, which is not actually used even on modern top cards, like GTX480 or GTX580.

STEP 4

Now familiarize yourself with your new creature. Comfort it with some attention.

Links are clickable here.

So we have next stuff there.

Top side



Back side



So master chip U41 (on right side, near FAN connectors) controls six phases to make ex-GPU power. U59 controller is controlling single phase on left, for memory etc. We could use that single-phase for some aux power. It's able to do ~40A current output, with up to 2V range. Main one is rated near 200-220A with same voltage range. Both controllers are adressable by SMBus/I2C interface, they have different address on bus. Empty pads on top - are transient response testing feature, we don't need that for us yet.

STEP 5

Now check if resistance of main power planes is good.

First - +12V inputs. Use your DMM, set on resistance measurement mode, with 200k-2Mohm range. Connect black probe to GND pin, red one to +12V input pins.



Normal:

>20kohm and raising, as capacitors charges.


NOT normal:

Anything below <10kohm.


STEP 6

Now check outputs



Same principle, DMM set to 200kohm range or similar



Connect black probe to ground pin, same as STEP 5, red one - to VCCP side of output capacitors, or inductor chokes.

Normal:

Some value in range 10-100kohm, changing as capacitor charges.


NOT normal:

Anything below 100ohm.


Same with memory single-phase output



Notice the range, there is 100ohm burden resistor on this output, so you should have 200ohm DMM range to check this VRM output.

So normal here:

50-100ohm range.


NOT normal:

Everything below 10 ohm.


Also check resistance between outputs, and between +12V. It should not be less then tens of kiloohms there. If it's close to short - find the short and fix it.

STEP 7

Thanks to Vinbo for support
__________________
xDevs.com

Last edited by TiN; 02-13-2011 at 05:01 PM.
Reply With Quote
  #2  
Old 02-13-2011, 11:30 AM
TiN's Avatar
TiN TiN is offline
Volt-Nut :)
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,458
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Default

STEP 7

Now we need to redo connections which left on cutted side of videocard PCB. These include +3.3V auxiliary power, sense lines, +12V.

VRM chipset itself need +3.3V on it's power pins to operate. Original videocard take +3.3V from PCI-Express slot. We don't have it anymore now.
Need to bring it back.

There are two ways to accomplish this task.

Way one, easy, for lazy people who don't mind having mess in their creatures.

Take +3.3V from SATA or ATX24 pin of target system where zombie will reside, and connect it to PIN 14 at U24. That's all needed to bring +3.3V
Then skip to STEP 12

Way two, for those who don't want to create extra mess, and prefer to have single +12V input to zombie, and no extra wirings
Follow next STEP 8

STEP 8

Acquire next components from your neares retailer or some dead hardware around.



It's simple adjustable output LDO which can source up to 1.5Amp of current, few tantalum caps, few MLCC ceramic caps, 220, 330 and 390 ohm and 2kOhm 0603 resistors. (if you skip LED you can skip 390ohm). These components are not rare, almost everyone have them.

STEP 9

Now take our creature backside up, and cut upper copper polygon to make some rectangle unconnected copper area, as shown on pic



This will be our +3.3V plane from LDO.
It shound not short to GND plane!
Be careful not to cut internal layers too. I used sharp knife for that task.

Now do some shrr-shrr-shrr to open copper areas from red protective soldermask.
Do it like this:



STEP 10

Now use your components to align everything for future curcuit surgery.



Notice upped right leg of LM317 LDO chip, this will go to nearest +12V input pin for Minifit-JR connector with short wire.
Left leg is placed on small copper area not connected to anything right now.
Tab of IC is on our big square area.

LED there is just to show we have the power If you dont like LEDs you can skip it.

Now solder the stuff with 40-60W solder iron. I've used ERSA 40S for that.



330 ohm resistor connects small area with left leg to ground. Right connected to +12V input and input tantalum cap rated to 20V.
220 ohm resistor connects output plane with small area with left leg. There is also 2000ohm resistor in parallel, to finetune output voltage to +3.3V.

In final you should get this.



Take notice on shorts on MiniFit-JR connectors. These are sense pins connected to ground.
LED cathode is connected to GND plane via 390ohm resistor, LED anode connected to +3.3V polygone directly.

Simple curcuit, isn't it?

Do not confuse TCAP polarity, marked side is POSITIVE for them.

STEP 11

Recheck everything. Recheck STEP 5 and STEP 6!
If everything is okay, get some ATX powersupply, connect zombie with 6+8 pin connectors and power PSU up.

If you did everything correct, you should get +3.1V - +3.4V on output plane with LM317 metal tab. LED should lit nicely.



I got +3.298xx VDC there.

STEP 12

Our small power curcuitry is not powering anything right now, it's just making power for LED.
We test it, and it seems okay. In this case we now can apply power to our zombie controllers.



Now take small piece of wire and connect our LM317 +3.3V output to 14's pin on flip-flop logic chip on back (U24).
This pin is VCC input and it's interconnected to all +3.3V points on our piece of PCB, including volterra masters and slaves. If you have patience you can try to find +3.3V points for yourself I'm ok with that pin 14.

Then take bigger heavy wire (AWG12 e.g.) and make +12V short as on pic. This way we will have +12V from minifit connectors go to of power plane of ex-PCIE-power. This is critical to function.

Everything should be clear by now, it's already time for some magic.

MAGICAL STEP 13

This step have mysterious action involved.



Remove Q45.



Connect R386 to ground (on capacitor empty pad nearby)
Connect R384 to VCCP output point on one of output capacitors.

Take care not to short anything else there. If you lost that R386/R384 0402 resistors - no worry ,they are just 0 ohm jumpers, you can solder short there.

Macro close up



Recheck everything again. No more magic steps right now

STEP 14 - TADAAAM...

Now again check resistance on keypoints, any shorts, errors etc. Everything must be perfectly connected.

If you still don't listen to me - apply teh power to input sockets.
I've added burden resistors as load on unit, to check if it can handle some amps.

0.1 ohm 10W resistor and 0.2 ohm 5W resistors there take about 15Amps from main VRM section.



0.979 V output present. ~60mV ripple.

"memory" single phase on second volterra block



1.827 V output present, ~48mV ripple.



Unit is ready for basic experimenting.
Assemble stock heatsink part for VRM cooling and/or have good forced air venting by 80-92mm FAN over it, because it's warming quite noticeably during operation.
__________________
xDevs.com

Last edited by TiN; 02-13-2011 at 05:55 PM.
Reply With Quote
  #3  
Old 02-13-2011, 11:30 AM
TiN's Avatar
TiN TiN is offline
Volt-Nut :)
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,458
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Default

Previous post show how we created zombie from high-end videocard.

But this VRM is not very easy to adjust during benchmarks, because Volterra chipset dont have feedback by usual meaning.
We need kind of digital controller to easily regulate voltage outputs from this zombie.

You can use EVGA EVBOT for this VRM, because it's SMBus-controllable.

This section is ADVANCED one, and for guys who are willing to learn hard.

STEP A1

TBD

STEP A2

TBD

STEP A3

TBD

STEP A4

TBD

STEP A5

TBD

STEP A6

TBD
__________________
xDevs.com

Last edited by TiN; 02-13-2011 at 05:50 PM.
Reply With Quote
  #4  
Old 02-13-2011, 11:45 AM
Cyph3r_Smurf Cyph3r_Smurf is offline
Dry Ice
 
Join Date: Sep 2010
Posts: 201
Default

Great Thread But my thought would be to add just a bit theory before next step. Then people might can do some of the steps by themselves next time and learn alot more.
Reply With Quote
  #5  
Old 02-13-2011, 11:49 AM
TiN's Avatar
TiN TiN is offline
Volt-Nut :)
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,458
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Default

Theory is here, little here, there So I dont think it's good idea to mess theory and practice together a lot. This is practice thread, because people are not willing to learn theory and that's it
__________________
xDevs.com
Reply With Quote
  #6  
Old 02-13-2011, 01:08 PM
FatAlbert FatAlbert is offline
Sub-Zero
 
Join Date: Sep 2009
Location: Europe/ Poland/ Rypin
Posts: 100
Send a message via Skype™ to FatAlbert
Default

TiN, is it possible to solder this to motherboard and use it instead of motherboard pwm ?
__________________
no cash Venom Lover <3

I don't write posts because I have nothing to say when you are extreme I am a noob without good hardware to extreme oc and only with dreams
Reply With Quote
  #7  
Old 02-13-2011, 02:20 PM
TiN's Avatar
TiN TiN is offline
Volt-Nut :)
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,458
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Default

Sure, not difference what is load.
__________________
xDevs.com
Reply With Quote
  #8  
Old 02-13-2011, 05:46 PM
TiN's Avatar
TiN TiN is offline
Volt-Nut :)
 
Join Date: Jan 2010
Location: Taipei
Posts: 1,458
Send a message via ICQ to TiN Send a message via Skype™ to TiN
Default

Updated.
__________________
xDevs.com
Reply With Quote
  #9  
Old 02-13-2011, 05:59 PM
Cyph3r_Smurf Cyph3r_Smurf is offline
Dry Ice
 
Join Date: Sep 2010
Posts: 201
Default

Getting a 2900XT home this week so i ca follow you.
Reply With Quote
  #10  
Old 02-14-2011, 01:38 AM
Hondacity's Avatar
Hondacity Hondacity is offline
Worries Too Much About User Title
 
Join Date: Oct 2009
Posts: 405
Default

damnnnnnnnn

that multilayer sandwich shot is awesome

i hate steps 8-11 ..lol
Reply With Quote
Reply

Tags
2900xt, engineering madness, overclocking solder guys, zombie


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 02:47 AM.

Contact Us - www.kingpincooling.com - Archive - Top
Powered by vBulletin® Version 3.8.3 Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.