Gameboy - Powers up but no sound or display

[AndehX]

Hi guys,  I have a gameboy here that seems to power up fine, but I get nothing on the display, and no sound (meaning its not booting games)
I have confirmed that the screen and speaker are good in a different Gameboy, so the problem lies on the logic board somewhere.
This Gameboy has pretty bad battery corrosion which I have cleaned up, and there appears to be no damage to the board, but I just thought I would mention that.
I replaced the little DC board with a known working on, still nothing.

What kind of things can cause a Gameboy to not boot games?  Dead capacitors?  If so I can replace those easy enough.

Any advice would be appreciated.

Cheers.

[kendrick]

So this is just a shot in the dark, but my experience is that 80 percent of the failures that fit this general description have a corroded cart slot. Used to be that on the original Gameboy, it was the corrosion on the cartridge contacts that went bad (in some random order) making it give up on trying to access anything on the ROM chip. If you have it open up anyway, take a continuity tester into it and see how badly knackered those little copper bits are.