I so opened the cable and there seems to be no cable running from PIN 4. I noticed that it now restarts the DMG when wiggling the cable. This only happens with 2 of my dmg's other 2 are fine...

Maybe something inside is shorting when link port is bent or something like that ... any idea's ?

I'll have a look into that ! Thanks for the help

No, the DMG is fine. The cable is bridging the 4th pin in the link port to something which disables the dpad.
It is a function of the dmg to have this pin controlled over the link port, but I can't think of any official or even homebrew application that utilizes it. Whatever cable you've bought must for some reason have this wire present.

Yeah if I plug everything in, all works fine except the dpad, then when I lift the plug from the cable a bit up or down, or when I just put my finger on it and apply some pressure the dpad starts working. So problem would be inside the cable then ? Not my dmg's ?

When you put pressure on the link port? It must be link port pin 4 which connects to the CPU's P14. This directly controls the dpad inputs:
http://gbdev.gg8.se/wiki/articles/DMG_Schematics

Your link cable must be connecting this pin to something it shouldn't be. I suggest actually removing the wire on pin 4 from your cables if it is present. Can you open one of your cables and find out?

Hi guys,

So I've been getting me some gameboys and a link cable. I was lucky to buy 2 nanoloops 1.5 a couple of years ago and forgot about it till now. But i'm having a problem with one of my DMG's when I plug in the link cable in both dmg's the d-pad stops working on one of the gameboys. When I apply some presure on the connector it works fine.

Any idea's what the problem is here ? I have 4 gameboys laying around and 2 of them are having the problem