Game boy color problem AKA "no nintendo logo"

[ASSEMbler]

You know the story. You put a cart into a GBC or GBA and turn it on,
only to see a garbled nintendo logo or one that is completely black.

You pull the cart out, put it back in, clean it, blow on it,
pray to Baal and nothing works.

So what is the flaw in the system that causes this?
Is it a certain pin?

[ave]

Doesn't that only happen if the cartridge is not properly inserted or some pin does not have any contact to the slot (i.e. due to dirt)? Thats at least what my memory says, maybe there are some other technical issues that could trigger the black block logo, maybe you should open it and have a look if there's something wrong with it.

[ASSEMbler]

I'm wondering if it's a certain pin that's the problem.

[Taucias]

It could be a number of pins. Is it only with certains carts, or all carts?

[ASSEMbler]

I'm wondering if it's the edge pins that are the main problem.

[raylyd]

i never work on many nintendos but try useing a sowing needle and bend pin one each pin and see if thats works

[Calpis]

The logo is stored in a ROM inside the CPU, if the black bar doesn't even come up, there's something wrong on the inside.

[ASSEMbler]

Well if you have a problematic game, the nintendo logo will be scrambled or solid black. Changing to another cart, it works fine.

The sewing needle is interesting, but as the unit is not mine I can't do that.

[Calpis]

The BIOS reads the game header expecting to find a copy of the logo, if it doesn't find it, it doesn't start the game. In order to read the ROM, practically all signals need to be working.

[ZueriHB]

If the Logo does'nt show up or is garbled, there is mostly a problem with the cartridge connectors, try cleaning the pins on the cartridge side with a q-tip and some hot water.

[Trenton_net]

I've had the exact same issue with Chinese multi-cards before. I've seen it where the PCB is too thick or too thin. In the former, it causes the pins to get bent a bit too far back than regular cards do. In the later, the PCB is too thin and sometimes doesn't always connect.

But I guess it depends on how used your gameboy is, and what kind of cart your using now.

[retro]

If the Logo does'nt show up or is garbled, there is mostly a problem with the cartridge connectors, try cleaning the pins on the cartridge side with a q-tip and some hot water.

Water in a catridge? Err, nah. Use contact cleaner. It even comes with a directional tube to get in the slot easily. That evaporates in seconds - water doesn't.

[ASSEMbler]

I already tried contact cleaner. I'll try plating the contacts.

[Tatsujin]

99.8% alcohol also brings wonders to day :)

as somone state already, if the logo is scambled or a black bar, one or several signal(s) on the cart port do not work properly. i don't think that it is a specific pin which causes the effect.

[kendrick]

I had a Castlevania Legends cart with this behavior. It turned out that the ROM chip was lifting up off the PCB and there was only intermittent contact. No amount of cartridge edge cleaning will fix that. Fortunately, I have an SMD rework station and I was able to blow hot air over the chip contacts, reflowing the solder and renewing the connections. I would consider that fix only after exhausting all the cleaning options, though.

[ASSEMbler]

Hmm interesting Kendrick.