Matrox Analog Edition and vga sockets

Yesterday my Matrox stopped working properly after we set up new cables … we spent about 2 hours trying to find out what was wrong, I assumed my Matrox was dead until I went back home, plugged it to my laptop with a cheap vga cable and it worked right away.

Until Monday I won t have the chance to check it out but I think that the problem lays on the fact that thos elong vga cables we used are missing a few pins and I guess those pins are sending the EDID information to the connected computer, missing this kind of info, the computer will use some standard (VESA?) resolution which the Matrox of course can t work with.

Has anybody had any similar experience and can confirm this?

Is it possible to store the EDID info for a device so that it can be retrieved by the video card without actually “being there” ?


you should always use the supplied short cable that comes with the matrox or a really high quality not much longer cable. quality and length is key. it such a high res going down the cable that a long cable just won’t handle it.

surprised you’re cheap cable worked with the laptop so yeah missing pins isn’t going to help either, does depend what res you trying though. 3x800x600 will go down a cheap cable easier.

rule i use is use the short one supplied and if coming out of DVI port use the short DVI to VGA cable cos cheap DVI<>VGA adaptors will mess it up too. Then use long cables from the outputs on the TH2G to projectors. If these are long runs too ensure really HQ cables because TH2G have a bit of a reputation for weak signalling and I’ve experience this too on very long runs and needed line amps to fix.

there is another part of the story I haven t told. Yet.
The first day we set up the long cables it worked just fine, and I kept my machine on purpose working for a few hours to be sure that the connection was alright.
Then a few days later it didn t work.
I assume that the first day we had firstly the laptop connected with a short, full pins cable connected, so the video card read the EDID info, Then we layed the new cables and plugged back the laptop, so it still had that info stored (just assuming here).

Anyway, using the supplied cable plus 2x vga to rj45 adaptors seems to be the way to go.

sounds like signalling. th2g seem really reliable. only every issues i’ve seen have been due to signal.BTW, the 3h2g <> PC and 3h2g <> projectors are completly different circuits. The PC will never know what projectors, if any, you have plugged in.

yes I understand perfectly that the input and outputs of the Matrox are completely different, the output can be happily coupled with VESA standard resolution while the input needs to be identified by the source.

So tomorrow morning I ll be able to do some more testings, but I think that the final setup will be

                          -----> long vga cable (already installed) ---> projector 

Laptop(3072x768) —> Matrox
–>vga to rj45 <----> rj45 to vga ----> projector

I can confirm now my suppositions: vga cables with some missing pins won t be able to read the resolutions of TripleHead2Go Analog Edition (no problems with digital editions), also, if you previously plug the Matrox with a full pins cable and then switch to a ¨missing pins¨ cables it may work because the video card saves the latest resolution settings

of course there are also products for EDID-management.
some of them: