What model of the GBA SP do you have ags-001 or ags-101? If you are not sure, check the label on the back of the GBA SP and it will be listed in the top left corner. If you have an ags-001, which is the launch model, it is frontlit as opposed to the ags-101 model which is backlit. I have a GBA SP Special Pikachu Edition that I got for my birthday in 2005 and I have never had this problem. I also have an original Gameboy Advance that I modded to have an ags-101 screen and I have never had a problem like that with that system either. The only time I've seen something like that with a GBA SP is with the ags-001 model and that's always going to happen because of the way it is frontlit.
I a fairly certain, both from looking at the images included in the guide and from examining the way that the circle pad is set up on my 3DS, that you only need to remove the cover, back housing and backing of the circle pad to be able to replace the circle pad cap. As far as I can tell, there is nothing that prevents you from removing the cap with the motherboard still screwed into the upper housing.
I a fairly certain, both from looking at the images included in the guide and from examining the way that the circle pad is set up on my 3DS, that you only need to remove the cover, back housing and backing of the circle pad to be able to replace the circle pad cap. As far as I can tell, there is nothing that prevents you from removing the cap with the motherboard still screwed into the upper housing.
I have a Surface Pro 6, and it identifies the SSD as a Samsung-made one. This is how it is identified in the Task Manager:
Disk 0 (C:)
SAMSUNG KUS020203M-B000
Capacity: 119 GB
Formatted: 119 GB
System disk: Yes
Page file: Yes
Type: SSD
Read speed 8.2 KB/s
Write speed 4.1 KB/s
Active time 1%
Average response time 4.5 ms