GBA SP (AGS 001) Screen Connector Problems

[Vector273]

Hello everyone!
I just bought a defective GBA SP after succesfully repairing a few GB Colors, Advances and an original. After receiving the SP i quickly noticed that the Screen was not working. I got a working one here so i used the Screen to test the mainboard but still no success. I googled a bit and found nothing helpful so i came here to share my sorrow and hope for help.
Do you guys think it makes sense to reflow the screenport? Or switch it completely?

 

[MichiS97]

Hiya,

to be honest I don't think the connector is at fault here if there is no visible physical damage. Can you upload some pictures of the mainboard and closeups of the port?

 

[Vector273]

Sure thing, here we go:

 

[Vector273]

 

[Vector273]

I do not think that there is visible damage... What else could be the problem?

 

[patters]

Have you checked continuity across the fuse? There's a fuse near the power switch I believe which blows if there's a short. I think this is often blown if there is water ingress. There are YouTube videos showing this kind of repair.

 

[Vector273]

Would the green power LED still work if the fuse was blown?

 

[Vector273]

It is still working, just checked it.

 

[Vector273]

Do you have another idea?

 

[Vector273]

Have you checked continuity across the fuse? There's a fuse near the power switch I believe which blows if there's a short. I think this is often blown if there is water ingress. There are YouTube videos showing this kind of repair.

Now i think i got the reply working, sorry!

 

[tech3475]

Things I can think of:
1) Try the 'faulty' screen on another working unit
2) Check the voltages on the pins for the connector (remember the light can be changed)
3) Visually check the solder joints with a magnifying glass

Found some schematics, don't know how valid they are.

 

[Vector273]

Things I can think of:
1) Try the 'faulty' screen on another working unit
2) Check the voltages on the pins for the connector (remember the light can be changed)
3) Visually check the solder joints with a magnifying glass

Found some schematics, don't know how valid they are.

1) The faulty Screen works on another unit, without flaw.
2) I will get to that, wich pins should i check? Could you share your Shematics?
3) Checked them, they look good, not different from a working unit...

 

[tech3475]

1) The faulty Screen works on another unit, without flaw.
2) I will get to that, wich pins should i check? Could you share your Shematics?
3) Checked them, they look good, not different from a working unit...

I found this with a quick search but I can't verify it:
https://github.com/Gekkio/gb-schematics/blob/main/AGS-CPU-11/schematic/AGS-CPU-11.pdf

There may be more elsewhere.

 

[Vector273]

I found this with a quick search but I can't verify it:
https://github.com/Gekkio/gb-schematics/blob/main/AGS-CPU-11/schematic/AGS-CPU-11.pdf

There may be more elsewhere.

Well, there does not seem to be any voltage. Even though there should be 5V.

 

[tech3475]

Well, there does not seem to be any voltage. Even though there should be 5V.

I'd then follow the schematics to find out where the voltage should be coming from and where it stops.

 

[Vector273]

I'd then follow the schematics to find out where the voltage should be coming from and where it stops.

I did, and i got the backlight up and running again!
But nothing else. I attached the speaker and can hear the startup sound when i turn it on, together with a working backlight. But noch Picture whatsoever. I am starting to fear it could be a completely faulty mainboard.

 

[Robika]

I did, and i got the backlight up and running again!
But nothing else. I attached the speaker and can hear the startup sound when i turn it on, together with a working backlight. But noch Picture whatsoever. I am starting to fear it could be a completely faulty mainboard.

I have a an SP with the same issue. I will be out of town till Tuesday next week but I can chip in with the testing and see if we can figure something out.

Same Issue, console boots, sound is fine I have back light but image is almost invisible. I will upload images later.

 

[Vector273]

I have a an SP with the same issue. I will be out of town till Tuesday next week but I can chip in with the testing and see if we can figure something out.

Same Issue, console boots, sound is fine I have back light but image is almost invisible. I will upload images later.

That would be great, thanks!
I think if you can barely see something you could try to adjust the cintrast screw under the battery.