Hello all, first time posting and all that, this is going to run a bit on the long side, so bear with me here.

I have an old French PAL SNES (SNSP-001A (FRA)) that just doesn't seem to want to work. Basically I remember buying it from an online auction years ago with the intent of modding it, but I never could test it until recently because I didn't have nor could find a suitable power suply for it because even though it's requirements are the same as a normal PAL machine (AC 9V, 1.3A), the french SNES is different from the usual PAL SNES', or at least the usual Scandic one's I've seen, that the prong in the power connector is thicker and a normal connector, like the one that would fit a non-Fench PAL SNES or a Super Famicom, won't fit, so I promptly just stashed it away and forgot about it. Finally now after recently remembering I still had the thing I started looking up where could I get a suitable power lead for it and found out a PAL NES power supply (NES-002E) works and fits perfectly with it, so I got one locally for way too much basically and after getting it on my hands immediately tried does it work with the SNES by simply hooking it up without a game or TV, and it seemed to work as the power LED lit up, I even left it on for about an hour and it still seemed to still function although getting a bit warm from the bottom like normal, so naturally I thought the machine works fine.
Later on I wanted to see does it work with games too, so I hooked it up to my '50 LED TV (Terrible I know, but I don't have a CRT anymore) via an official GameCube composite SCART cable, plugged the power in and popped in Choplifter III, powered it up in anticipation, and... nothing; No picture, no sound, just darkness. Naturally I tried hard resetting the game a couple of times, hammering the reset button, fidgetting with the cart while it was connected, blowing in the game's connector and then in the console's, all the usual procedures but still nothing, no blowing shit up with a chopper and rescuing prisoners for me. Tried another game too, didn't work. At first I thought maybe the video cable was the problem, the FRA SNES is a marvel again because it doesn't have an RF connector but only the Multi AV port and AFAIK the console was shipped with an RGB cable instead of composite like the rest of the world because France is awesome like that, so I tried hooking up an official GameCube RGB SCART cable with it, but nothing, still just darkness. I read from the internet that supposedly the GCN RGB cable doesn't like to work with a SNES, but it was a bit vague is it only with an NTSC model or all of them, but nevertheless I came up with this article about fixing the cable and making it work with a SNES, so I followed the guide and did the fix, tried it again with the SNES and it still doesn't show shit.
At this point I was pretty stumped about what the hell could the problem be, so I opened the SNES to have a look around could I find some obvious fault with it, but nothing seemed out of the ordinary; no pins or wires broken, no connectors loose, nothing smelled like it would have burned, nothing. At this point I took the chance to clean the cartridge connector by the usual means of contact cleaner fluid, q-tips and a cloth + credit card combo to see would that help, but in short it didn't, still doesn't work. Next I tried to see was the problem with the TV, who knows about these modern crap TV's do they even work with systems this old, so I made sure the channel was correct, - there is only 1 SCART channel on it though, small wonder it even has one - and that it was getting a signal, which it was because the TV info says so and I can always see the screen doing stuff when I power the SNES or reset it, but just no game. I even double checked with my SFC does a SNES even work with the TV and it did fine, just the picture is green from the RGB cable, but fine from the composite, so the problem most surely isn't the TV or the cables. Next, to absolutely cross out the cables and TV, I tried it with another TV, which again says it's getting a composite signal from the SCART, but no picture or sound.
After all that, I tried looking up from the net could I find some help there, but nothing solid except that apparently some PAL SNES' don't like to boot with different region controllers attached, which shouldn't be a problem as the pad I have is a PAL SNES pad (SNSP-005) but nevertheless I first tried booting the system without a pad connected at all, then just for kicks with a SFC pad, but both failed, then I tried to override the controller lockout alltogether via this guide to see was that the problem somehow, but still it doesn't work.
So next I turned my attention to the cart connector, even though it seems fine with only a little external deterioration, I nevertheless removed it as it's easy on these PAL SNES models due to it just being attached via 2 screws to take a look at it closer, but by my own eysight I find nothing wrong with it and the connector that's attached to the board via solder seems fine too, but I remember reading about something somewhere that reheating the solder points in the connector could fix some problems with it, so I tried that next by heating all the 53 or so pins under the board by soldering iron, but it didn't work. Then I remembered my other, broken PAL SNES I have that also has a removable cart connector, so I thought maybe I'll try exchaning it's for the French one's to see if it works, but I found out I might have possibly already done that as the other SNES is missing it's connector, maybe the French SNES was sold to me originally without one and I just promptly forgot about it, so scratch that idea, although I am wondering could it just be that the connector is somehow a wrong type and doesn't work in the French model, like a different pinout?
Lastly, out of any better ideas I thought maybe the console's lockout chip is busted, so I lifted pin #4 from the lockout chip like how you usually make a PAL SNES region free, but it didn't work, the console still doesn't work.

So right now, I'm completely out of ideas as to what the hell is the problem with it or how could I fix it. If anyone here has any suggestions or help, it would be very much appreciated because I've wasted way too much money on this POS already and would very much like to get it working so I can mod it and sell it for cash money