GBA SP Capacitor Diagnostic
If you're unsure about whether your GBA console needs a recap, you can test the voltage on the capacitor while the console is powered on. This is a common cause of no audio on a GBA SP console.
Measurements are performed with a multimeter in DC voltage mode. Read your multimeter's manual for full details on setup for your device.
These measurements are made easier using an power supply which can clip on to the battery terminals to supply 3.5v.
This test must be performed with a speaker installed, therefore you may find it easier to perform this test with the PCB screwed into the front housing to ensure the speaker is making a good connection.
Place your black probe on the side of the capacitor marked in black. Place your red probe on the side of the capacitor labelled '+'.
If your readout is significantly less than the voltage listed, the respective capacitor likely needs replacing.
The following measurements were performed on a known working board that has been recapped.