I've been having problems with my PAL gamecubes brightness levels.
The official cable I got with the system went missing and with another one I have I get the same brightness Issue (I believe the cable is from my NTSC N64 tho im not sure..) so I bought a cable off ebay and forgot about it until recently.
Now I've read online (and here too I believe) that I can fix the issue by soldering a 75 ohm resister somewhere on the cable or something?
This is the cable from ebay:


this is the official one i've got which I suspect is from my NTSC N64:

Both Cables work perfectly with my SNES. Colors are correct and theres no problems at all..
I would have suspected the console itself but the thing is Ive got 2 PAL gamecubes with a 3rd NTSC on its way and both PAL systems have the same issue..
So where exactly am I suppose to solder a 75 ohm resistor to the cable?
UPDATE:
I've done the mod and it worked! here are some pictures:



Don't mind my lame skills