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Radeon HD 4850 Voltmods

Discussion in 'Articles' started by W1zzard, Jun 28, 2008.

  1. Velvet Wafer

    Velvet Wafer New Member

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    sry for doublepost, but: card is clearly dead... i cant display even windows... just the windows load screen. i make it ready for an rma, what do you say?

    btw the other problems dissapeared somehow, after reconnecting every power cable leading to my drives, and to lay the ide maindrive and the fans on different connectors. pleased me somehow...
     
  2. Wile E

    Wile E Power User

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    Did you try uninstalling the drivers in safe mode, then reinstalling them? A corrupt driver install will cause that issue. If that doesn't fix it, I'd say it's rma time.

    And sounds like you just had a loose connection somewhere causing your missing hard drives. Probably bumped it installing the card, or something like that.
     
  3. Velvet Wafer

    Velvet Wafer New Member

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    even when the driver is corrupt, the card should display the bios normally... no chance..

    looks like these, but 3 times harder and unclearer, and if i try to get in windows, the screen displays 40-50 1cmx1cm artifact rectangles which spread themself with 1cm space between them.

    http://img248.imageshack.us/i/screen9uf.gif/

    it could have been that i messed with cables, but normally my cable management should prevent me from doing so. at least the rig works again...
     
  4. Wile E

    Wile E Power User

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    Oh yeah, that's RMA time for sure. Dead memory on the card.
     
  5. Velvet Wafer

    Velvet Wafer New Member

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    it died from a tiny scratch of pencil... very cheap ram... my last ran fine with 2.3 (a short time) until i removed it. but no artifacts or even something in this direction. just heat-crashes because of the vf-900.

    are RMAs of RMA´s accepted? i mean, do they make problems if an RMA-Part gets RMA´d?

    ill send the card in on monday... it not even 2 weeks here then...
     
  6. Wile E

    Wile E Power User

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    Yes, you can RMA an RMA, as long as the warranty is still good on the original card.

    And are you trying to use a vf-900 on these cards? If so, stop it. lol. The vf-900 is overpowered by these cards.
     
  7. Velvet Wafer

    Velvet Wafer New Member

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    lol no i got a toxic... its delivered with it... for OC-purpose i got myself a twin turbo, lapped ;-)
     
  8. cr1pz

    cr1pz New Member

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    Hey ! wassup everybody :)

    Hey velvet you might have read about peltier cells , haven't you ? I found out they're really cheap in my country ! lol , do you think is a good method for cooling a vga? I know they're really cool as much as you manage to keep the hot side cool.

    But what i don't know is that issue with the power ,I mean there are some cells working at 136 watt , some other at less power range , maybe 56 watt in fact those are cheaper...
    I'll keep gathering intel in order to get the best option ;)
     
  9. Velvet Wafer

    Velvet Wafer New Member

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    if you plan on using peltiers, combine them with a watercooling loop and insulation... if one fails, your card isnt too prone to dying... if you put the peltier directly on the core, chances are high, that if it fails, your card will fry in seconds, or if youre lucky, it will shutdown immediatly...

    i wouldnt use peltiers for anything other than chilling water. its too dangerous, even if its cheap and effective (if you plan on removing the additional peltier heat, dont use air cooling.... this could be toasty in a case, you should at least use water... so you see... peltiers are not the best idea, you WILL have to invest in Water, if you want to keep it cool AND safe)
     
  10. Wile E

    Wile E Power User

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    You need to water cool a peltier for it to be effective. You should also have a dedicated power supple, just for the peltier. Now, throw in the fact that most gpu water blocks can only fit 40x40mm peltiers, and you can only get 80w peltiers in 12v. Not worth the effort at all. You could look at 24v peltiers in 40x40mm, but then you need to buy a 24v peltier power supple, which is usually a little more expensive.

    It actually becomes very expensive to run peltier cooling on your graphics card. It's not worth the trouble.
     
  11. cr1pz

    cr1pz New Member

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    I am planning to do some water cooler anyway ,but as I see , it'd be enough with the WC , enough to keep a good range of temperature and to avoiding accidents ..
    thank you guys ;)
     
  12. Velvet Wafer

    Velvet Wafer New Member

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  13. overclocking101

    overclocking101

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    ok guys i did the hardmod! i figured someone on the forums had to right??? well here it is in all its glory the core resister need to still be glued down same with the vcore/vmem molex reader but its done all the same soon as i plug it in ill hit you up with screen shots!!!
     
    Last edited: Dec 11, 2009
    Scrizz and theorw say thanks.
  14. theorw

    theorw New Member

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    :toast:
     
  15. Scrizz

    Scrizz

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    let's see how high you can clock that sucker.
    penciling mine game a 225MHz increase over stock :cool:
     
  16. Wile E

    Wile E Power User

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    Be careful with the mem voltage. My experience with it shows that GDDR3 is pretty sensitive. I quit doing vmem mods for 24/7 use. I do it on benching cards only.

    And I vmodded my 4850 30 minutes after I got it. Popped it in to make sure it wasn't DOA, took it back out, fired up the soldering iron, did the vgpu mod, threw a water block on it, and threw it back in. lol.

    1.4v got me to 900Mhz bench stable, probably around 870 game stable.
     
  17. theorw

    theorw New Member

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    Qustion:Can i use a 20KOHM resistor for the solder mod?
     
  18. Wile E

    Wile E Power User

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    No.
     
  19. theorw

    theorw New Member

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    Why is that?
    Could u explain please?
     
  20. PVTCaboose1337

    PVTCaboose1337 Graphical Hacker

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    Ok so you don't want to do this because of Ohm's law. In other words, the amperage of the card would be too high, as well as the wattage.

    [​IMG]

    And if you still don't get it, IT WONT WORK.
     
    Last edited: Sep 17, 2009
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  21. overclocking101

    overclocking101

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    so far just tested for working vmod and it does work. after im done messing with my new 4870's (maybe vmodding them to) ill test for high clocks
     
  22. Wile E

    Wile E Power User

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    Thanks PVT. I have so much experience in electronics, that I just assume that everyone else understands the basic principles.

    @theorw - It's as PVT says. The voltage will be too high if you use a 20k ohm resistor. The lower the resistance, the higher the voltage. You need a 100k ohm 15(or higher) turn resistor for this.
     
  23. theorw

    theorw New Member

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    I know the ohms law guys...:cool:
    Just wanted to hear an explanation.I am studying electrology at uni and not electronics(houses are different that PCs...:D),i think the next year maybe...
    Anyway i just put 2 20kohm+a fixed 50ohms soldered together and it worked:toast:
    Now i get like 0.8 more volts and still i have to max out the 2nd 20ohm resistor!
    The problem is this.When i have my card @820 @1,30 volts it runs flawlessly every bench and game but @ 1,38 volts the system will shut down after 5 minutes.And NO its not overheating...
    Maybe my PSU is maxed out then?

    PS:check out my ULTRA pro voltmod!
    http://img9.imageshack.us/img9/9530/dsc01801df.jpg
    http://img21.imageshack.us/img21/1566/dsc01802y.jpg
    http://img9.imageshack.us/img9/2843/dsc01803kj.jpg
     
  24. Wile E

    Wile E Power User

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    1.38V idle? And what program are you testing with?
     
  25. theorw

    theorw New Member

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    Not idle.Load.
    Idle i get 1,29volts.
    gpuz 'course...
    U reckon the card cant handle it?Should admit its almost a year @1,33volts@821mhz core and 1200mem.
    Could it be that the vrms have aged faster?Or that the card cant handle that much volts?
    I got musashi on it,u keep in mind!
     

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