The Dummy Plug Thread!

Thought I would put a quick dummy plug thread up for people that dont know about them, why you need them or want to build some.

Basically you only need them if you are running Vista (32 or 64 bit) and are running multipule GPU's. Vista is clever and if it cannot see a physical monitor conencted to a 2nd graphics card it will not enable the GPU meaning you can not fold on it.
XP is ok you can simply just right click the monitor in display settings and select 'Attached'

Also good to remember even though most graphics cards have 2 x DVI outputs on them you will only need to put a "Dummy Plug" on one of the outputs UNLESS its a Pre-Sli'd graphics card such as the GTX 295 or 9800 GX2!

There are random threads all over the interweb about them but I have made quite a few now which doesn't use the push raw resistors into DVI-VGA adapters as I didnt trust them for a 'solid' reliable conenction.

Shopping list from Maplin Electronics (www.maplin.co.uk):

3 x Metal film 0.6w 75Ω Resistors: code: M75R £0.45 (15p each)
1 x D-Sub HD 15-Way Connector: code: JW78K £1.69
1 x Snap-Lock D-Sub PlasticHoods: code: KE95D £1.69


Heres some I have made up this week and show you how to do it if you are handy with a soldering iron, otherwise I could offer my services and build some for people, if you want some making just drop me a PM

 

IIRC from another post, using CUDA drivers 2.1 and above removes the need for dummy plugs in Vista. Can anyone confirm this is true?

 

You'd be referring to http://foldingforum.org/viewtopic.php?f=50&t=9805 well I cant make it work!

Just puts me in an unstable machine loop forcegpu my second card!

 

Ive not heard that myself yet, I tried the Cuda 2.1 drivers on one of my machines yesterday and it kept bluescreening so I had to roll back lol When I try it again on a fresh build I will try without dummy plugs...

 

Nice guide coolamasta, I love dummy plugs that have covered resistors rather than exposed ones! I will be making a few of these myself when it comes to running Vista on the farm

 

So you've settled on Vista, I thought you were leaning towards Linux

 

You need to read the thread a little more

The plan is to fold with vista on all but one machine, that being the linux runner... then when I am confident enough to run Linux on them all, make the necessary switches

 

OK - I hadn't caught up with the latest.

And sorry about hijacking the thread - seems dummy plugs are still required, and these ones look good. A useful contribution - thanks

 

You can make them even neater by getting DVI plugs and soldering the resistors to the analogue pins inside.

I'll post pics when I can get my a$$ down to maplins.

 

Maplins N40FB DVI-I single-link plug £1.49

It might be that a Maplins CT73Q hood for a 25-way D-sub connector would house it.
Edit: No, it is the wrong size

I resurrected a dummy plug thread last month from the old CustomPC forum.
resistors shoved into DVI adapter

I did not mention it, but I also made a dummy plug by taking an adapter apart and soldering resistors
to the VGA pins.

The captive nuts (called jack posts) on top of the adapter also act as rivets. I ripped them off with pliers.
I could then remove the top and the blue plastic around the pins. I soldered the resistors onto the bare
pins. Then I used epoxy to fix part of a large felt tip pen over the resistors.

While I was at it, I cut away the plastic from the VGA end of the adapter to see what is inside. The
body of the adapter is an oblong metal tube with the DVI plug at the bottom and the VGA socket at
the top, with wires inside. Some time I might rip the DVI end off and solder resistors to that.

 

Accidentally posted the same message twice.

 

The 39 way version of the hoods here look like they are suitable for the DVI connectors, althought the DVI connectors that maplin have on their website seem to be missing a large number of pins . The photo must not be of a Dual-Link DVI plug.

Tell you what, I'll take a spin into town in't mornin and buy a couple then show u guise what they're like

Oh and for the record, 15p per resistor is daylight robbery... I get any resistors for an average of 3p-5p each. Same with LED's. Maplin is such a rip off for electronic components I might start making the tidier versions of the DVI plugs with stuff from RS electronics. If the design works, they'd work out much cheaper for everyone.

Please post pics of this asap, or if you know of a guide that's just as good. I don't know the pinouts of the DVI plugs to solder the resistors to

EDIT: Think I got it;

C1 -> C5
C2 -> C5
C3 -> C5

Correct me if I'm wrong!

 

That's right.

 

Cheers saspro, 5am electronics logic Cheesecake!

 

Cool, did think about DVI dummy plugs but couldn't find any info about them on the quick look I had and I needed some ASAP.

Will be needing some more soon so will build DVI ones after you have have done yours, can you put pics etc on here so I can see?

And yeah 15p a resistor is expensive compared to RS but I couldnt be bothered to drive to RS so maplin had to do haha

 

Sure, I'll post my pics here once I make the DVI ones up

 

Judt went into maplin and they had no DVI connectors... USELESS! So I ordered them from the website instead. RS don't seem to stock them.

 

Bend pins C1, C2, C3, C4 slightly away from C5 to prevent a solder bridge. Trim a resistor
and bend the end into a loop that will fit snugly around C1, then solder. Repeat for C2 and
C3. Solder the other end of one resistor to C5. Solder the free ends of the other two resistors
to the lead you just soldered. I soldered all three to C5, but this risks leads coming off as you
solder the next.

Use needle-nose pliers or tweezers to hold the resistors or you will burn your fingers.
Don't hang the soldering iron over the computer monitor or you will burn your arm.
Err, forget that last one, that's just me.

You can use a dual link plug, it doesn't matter. That just has more digital pins and we are not
using any of the digital pins. You can use 68 ohm or 82 ohm resistors instead. If you only
have one resistor connect it between C2 and C5 and it will probably work.

 

Nice one ArtherBuse, will get some of them ready for the next batch

 

Thanks for the guide and confirmation on that ArthurBuse, I will get into finding some plastic hoods that are suitable for DVI connectors. I enquired about those that I mentioned above in maplin and they are actually for wider DSUB connectors such as serial and parallel ports.