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Hi there,
I was wondering if you guys who use dummy plugs could post what type of dummy plugs (with or without dvi-vgi adapter, what resistors (ohm), put into which holes of the port) you use and with which graphics card.

Which guide did you follow to build your dummy plug?

Did you put the plugs on before installing the OS and drivers or after everything was setup?


I actually had trouble building the 5-second version (putting a 75ohm resistor into the dvi port) for my two xfx 6870 black edition - did not work out and now I'd like to know what you guys do - to decide wether I buy a bunch of dvi-to-vga adapters (cheap) or get kvm switches (expensiv) :-)

Got an hdmi switch. Cheap and fast, especially if you don't already have an DVI-VGA plug.

can you please post a link to that switch?
do you need to attach a screen to it or is it enough to have the switch attached to the card?

http://www.overclock.net/folding-home-guides-tutorials/384733-30-second-dummy-plug.html

I used that guide, though I used 75 ohm resisters, which people in that thread said worked. Mine works fine.

Followed the same 30 second tutorial

worked fine w/ both 68 ohm .5W resistors and 75 ohm .25W resistors

buying an HDMI switch for this is nuts.  you can build dummy plugs for <$1.50 no problem in literally 30 seconds

Simply using a resistor, has worked fine for me, I followed this guide:
http://blog.zorinaq.com/?e=11

bought a pack of 50 resistors for $1, and they all work fine as dummy plug

I'm in japan and a 3+1 switch with remote it's around 20$, each DVI-VGA is about $5. Fry your card for a short will take time (aka bitcoins) .
So yeah, i proudly "wasted" 5$ on a hdmi switch with remote :p

how much are HDMI cables?  Does your HDMI switch require power?  Does it require intervention when you boot your computer or does it activate each GPU just by being plugged into the HDMI switch?

order DVI-VGA from China for $.99/each

Not quite sure what you are referring to by "fry your card for a short". 

My dedicated miner requires *ONLY* a power plug and boots directly into windows and starts hashing on all GPUs.  No intervention required, and no extra accessories hanging off the back of the rig

The switch is powered by the HDMI cable, just need to be plugged. Here, new gold plated HDMI cables are around 3$ (but i already got 3). False contact, short contact, resistor drops onto your mb can make you lose time. The cheapest DVI-VGA i found from ebay are from china and sold for 2.59$ and around 2 weeks shipping, the switch i got was "same day delivery".

If you are satisfied with your solution and you think it's the best i'm happy for you. But I, being an electronic engineer, i'm not going to stick unsoldered resistors into a vga plug.

haha and I had about a dozen dvi-->vga plugs so obviously I prefer dummy plugs :)

here is an ebay item for $.99 from hong kong with free shipping.  Does shipping from HK to Japan really take 2 weeks?  I figured you guys would at least get the benefit of being close by

i had so many of these things 6 months ago that I threw out 10-20  :-[

what graphics card? this was not working with my 6870..

You did it wrong probably, I've done it with 6870, 6970, 5830

how do i do it right? :)

if i have the dvi port in front of me, the "square" with the 4 little holes and the cross in the middle on the right side. where do you put the 75ohm resistors in?

For what's it is worth, in addtion to using 68 ohm and 75 ohm resistors (which are actually difficult to get because 75 ohm is not a standard resistor value), you can also use 82 ohm and 100 ohm resistors just fine. If you have 150 ohm resistors you can make 75 ohm resistors by connecting 2 x 150 ohm resistors in parallel.

I mention this because if you buy an assorted resistor pack from Radio Shack you don't just keep the 68 ohm resistors and throw away the rest.

If you are worried about blowing up your card, keep in mind that it is safer to go higher than 75 ohms rather than lower. 51 ohm resistors are also included in may resistor packs and those also seem to work, but because they draw measureably more current than 75 ohm resistors wouldn't recommend them.

here in Germany you can buy single resistors for 6 cent at Conrad Electronic :) and they have 75 ohm, too. But if I don't get this to work, I will buy a bunch of 82 ohms and see what happens. Not a fortune to invest ;)

Just a question... plugging in an old analog CRT monitor is just as good as a dummy plug, right?

For anyone not wanting to invest the expense in a KVM, or isn't comfortable crafting a plug, we do offer finished manufactured Plugs @ the cablesaurus.com site.

I used the dvi-vga plugs that came with every one of my vid cards...some 75 ohm resistors from my shop.  Took about a minute each...coated them in nonconductive paint on coating.

You need to put it in the VGA end of a DVI to VGA plug, not in the DVI port!

There is a way to do it that way as well...I don't have the pinout in front of me but I ran across it at one point.

67.5ohm

http://i51.tinypic.com/w02xkh.jpg

i tried that one with 75ohms, but it didn't work out. i wonder if there is anything you can do (i did) wrong while putting the resistor in ^^

graphiccard?
1/2 watt resistor? 1/4watt?

i've purchased 3x HD5830 i think they just give me a HDMI -> DVI Adapter, right?
i dont want to wait and spent more money on DVI->VGA adapters... maybe i got some at my parents house, but until i get there again could take at least 3weaks ;) so could somebody tell me the "5sec" dummy works fine? if not i probably have to use linux as OS... never used it before :(

also a question, do they deliver a 4Pin Molex to 6Pin PCIe power cable with a HD5830? (its a Powercolor HD5830 PCS+)
i've read a few reviews, some of them say there is a power cable adapter some of them say there's none :/

*edit*
with this 3 images:
http://upload.wikimedia.org/wikipedia/commons/5/5b/DVI_Connector_Pinout.svg
http://upload.wikimedia.org/wikipedia/commons/3/30/DE15_Connector_Pinout.svg
http://www.instructables.com/community/DVI-to-VGA-Conversion-on-a-Budget/

i came to a conclusion (not tested(!!!), but in my mind it should work 100%)

the DVI -> VGA dummy circuit connects the following plugs:
3 - 8
2 - 7
1 - 6
you can now see in the third picture that plug 6,7 and 8 are all connected with the C5 plug of the DVI.
Plug 1 is C1, Plug 2 is C2, Plug 3 is C3. If you now connect everyone of these three with an 68 or 75ohm resistor to C5 (look image1) it should be exactly the same as the VGA dummy circiut. Should work for everyone.

It seems some resistor don't work, I got a few 75 and 100ohm from radioshack, and they both worked. But I also ordered a big pack of 75ohm from ebay, and these don't work this way (but works when I use them with a vga converter). It seems the ones I got from ebay are a lot thinner than the radioshack ones though, but they both say 75ohm

Bend the lead over itself so that it doubles up...that is what I had to do with my DVI-Vga ones. 

i will try that when i have to rebooot the next time ;)

i was wondering if it maybe matters from which material the resistor is made of

It shouldn't unless there is some coating but that would be new to me (and I worked in contract electronics manufacturing).

Just the resistance matters...wattage is of little importance in this case too...I believe mine were either 1/8 or 1/4 watt resistors. 

Compare a normal DVI plugs pins...if your resistor lead is not similar size or larger then chances are it won't make proper contact...I bent the lead over itself then its double the size...then it fits nice and tight.

it's working now, with bend-over leads on one end (the one that goes into the "cross")
allthough not all resistors seemed to work

In this case all the 75ohm resistors are the same...when you get into RF, high surge current, or induction sensitive things then there is a difference...I wouldn't use any wirewound resistors on this stuff but pretty much any carbon film resistor over 1/4W should be good (well 1W leads probably wouldnt fit in the holes...there are physical limitations).

You have to remember...these plugs are meant to have pins going into them...not really resistor leads.

I'm going to try the 5 second method first, and if that fails, will do the 30 second method.

EDIT: I didn't do the 1 resistor method. However the 3 resistor method worked flawlessly! I also wrapped the middle resistor with electrical tape, then all three, so that they wouldn't fall off easily.

I use the "paint on" tape stuff to hold them in...insulates and holds them in place...it is basically just non-conductive red colored rubber cement.

http://www.amazon.com/dp/B00176FG0A/ref=asc_df_B00176FG0A1617225?tag=thefind0050295-20&creative=395261&creativeASIN=B00176FG0A&linkCode=asn

That stuff.  Just happened to have some laying around, I keep finding uses, great for prototyping electronics.

I have updated http://blog.zorinaq.com/?e=11 with a schematic showing C1-C5, C2-C5, and C3-C5.

OK, loooooooong st0ry short... I have a GTX570 in one computer that I used a dvi-vga adapter, scrounged my scrap electronics, removed a 176.2ohm(meter) and inserted it to connect pin 1 to pin 6 while the computer was shut down. Booted it with secondary monitor hooked up as "extended desktop" in win7x64..."null plug was hooked where my primary display is usually hooked"...after starting miner and watching for a minute, turned the monitor off and removed it.
 Went to the bedroom, hooked the monitor to one of my other computers, using VNC to check and all is well so far. NOTE< there is NO monitor hooked up to the mining computer, just the null plug(one 176.2ohm resistor NOT 3)  176ohm was all i had vs 50-150 as called for. Now that this is done, I may just remove the dvi-vga adapter and install the resistor straight into the dvi plug on the appropiate pins.
 Will let ya know if anything goes wrong.
 I revived this thread as it is the first one I found when doing my initial search and it has all the pertinent questions, answers and both ways of doing it complete with links to pix and info. As I had a value higher than called for, I was nervous but it was all I had. Out in BFE on a COLD day and I'm a wheelchair test pilot who isn't going outta the hut today BUT determined to get it finished or pHuck it up, I just wanna surf lol.
 If it's a problem resurrecting this thread, tell me and I will scratch this.
John

And you necro'd a 20 month old thread for what reason?

Dummy plugs nor resistors have not been necessary for a very long time now. The problem has been fixed in the driver.

Beg your pardon but not on my computers running win7x64. THAT is why I checked to see if a null plug had been tried.