This has happened to me but i've fixed it by retracing my steps. I've noticed that even a very weak magnet (of a fan for example) over top of the RAM chip prevents it from booting (OR it was just my gluing job that messed it up)
Sure but using that speaker size for such a minor increase in sound quality isn't worth it in this application imho. Pretty sure people use a headphone jack + small speaker config when they want the best of both worlds...just more practical really
That's a great find. Personally I like using a PS2 slim fan combined with a small heatsink, but yours seems good too! Have you tested it with any games?