Sorry I didn't want to go offtopic here and also I don't have the ejem... money to open another thread to repair it. Nope. The led works but I've got no image. It must be a chip that got fried somehow
Not sure about composite, I didn't try it after I got it working with the trick.
Edit: My only possibility would be to reflash the Indi in another Amiga and then install it again here... or a bootable/automatic reflash.