On the second image you posted, on the upper right corner there seems as It might be some damage. While they do appear fine It's still possible that the previous owner cut a some really tiny copper line. If you check online, you can find some images where the traces have been cut when attempting...
Try to hold the RSX or CELL down with a slight pressure (not too much) and while doing so, boot up the console. If It boots up normally while you're pushing It down, It indicates that there is BGA defect and will probably need a reball.
Hello!
After changing the thermal paste on my PS3 (CECH-2004a), the console wouldn't boot and would display the YLOD instead. After connecting to the SYSCON and reading the stored codes, It read 3034. If I lightly pressed down on the RSX during boot, the console booted normally so I assumed...