Doesn't show nintendo logo or black bar. Sometimes runs a game?
As described above, the gameboy doesn’t ever load the Nintendo logo (or black bar when no cartridge is inserted). No sound ‘ding’ either.
I know that the logo is a sort of ‘genuine hardware’ / handshake operation, but it seems that this is going wrong on this device.
The interesting thing is, about once every 10 hard resets (just off-on) it loads straight into the game, skipping the logo step entirely.