US Super Nintendo - No Image on Screen

I have a US Super Nintendo (Board SHVC-CPU-01) and it powers up fine but on screen (via composite) the screen flashes white 5 times and occasionally stays white with a black notch at top left. Pressing reset causes the screen to jump as would be expected. If I use an Action Replay then the menu comes up normally (so it finds the ROM on the cart) but then back to the black screen.
The game I am using to test works fine in my other SNES and the AV cable works on that too, so the problem is with the console.
I have replaced all surface mounted capacitors and only have C63 & C64 left (I'll do these once I get the parts but I suspect nothing will change).
I suspect a chip has died but would like to hear any suggestions.

 

Dead cpu

 

Or, if you're lucky some broken traces. But most likely dead cpu.

 

My guess as well.