Nintendo GBA blank screen when reading GBC games

[patters]

Edit. Nm, hadn't read the post properly.

 

[Uevon]

Well, I discovered something about my GBA SP since my last post; apparently when the voltage switch is down (or a Game boy game is inserted) there is continutity on the first solder joint (S1) holding the switch down, the one in front of S1 (C1), and the middle joint (S2). I don't think this is right, because when the switch is down, isn't there only suppose to be continuity on the middle joints, C1 and S2? Isn't the switch suppose to short the first joint? I tested with GBA off, by the way. https://www.reddit.com/media?url=https://i.redd.it/woduc7a2q5a71.jpg (not my image)

You know, I actually think its a problem with one of the cartridge slot pins. The first one is sticking out the farthest and is in kind of a C shape. is that normal?

 

[Uevon]

BUMP: I hate to keep piling on the questions, but for the sake of potentially having to buy a new cartridge slot, how can I test the solder points of the cartridge slot? (by the way, i tested via 32 with the mounting pin solder point and there was no continuity)

In my crude understanding of the Game Boy works, I know that the OG Game Boy Nintendo logo is contained in the cartridges, and must be displayed by the system itself. For that reason, if the switch is held down and the system is powered on without a cartridge, wouldn't this screen not be able to appear? Maybe I was wrong for thinking that meant there was something wrong with the system as a whole; I'm starting to think its not actually the board but something wrong with the slot, like maybe it needs a reflow.

 

[Ryccardo]

For that reason, if the switch is held down and the system is powered on without a cartridge, wouldn't this screen not be able to appear?

The "Nintendo" would become a black rectangle* due to correctly decompressing different data (from the open bus read), the "®" and the "Game Boy" come from the console, in any case something gets displayed

* talking about GB/C mode of course, GBA modes usually hides the loaded logo and the ® when no card is inserted but I don't know the specific details

The first one is sticking out the farthest and is in kind of a C shape. is that normal?

Dunno, should be a bit like this:

But certainly they should all look the same - at the same time, due to the above, it seems the slot is not the only or even the main problem...

As for the switch I don't remember the exact pinout but it should be on gbatek

 

[Uevon]

The "Nintendo" would become a black rectangle* due to correctly decompressing different data (from the open bus read), the "®" and the "Game Boy" come from the console, in any case something gets displayed

* talking about GB/C mode of course, GBA modes usually hides the loaded logo and the ® when no card is inserted but I don't know the specific details

Dunno, should be a bit like this:
View attachment 395756
But certainly they should all look the same - at the same time, due to the above, it seems the slot is not the only or even the main problem...

As for the switch I don't remember the exact pinout but it should be on gbatek

Hey, thanks for the reply. That drawing looks just like the pin in the slot. If the Game boy logo is suppose to be contained in the slot, doesn't that mean one of the pins has a short?

 

[Ryccardo]

If the Game boy logo is suppose to be contained in the slot

No, the "GAME BOY" comes from the bootrom which is inside the processor...

 

[Uevon]

No, the "GAME BOY" comes from the bootrom which is inside the processor...

So could the processor be what's malfunctioning if it can't display the proper graphics on screen?