[villagetinker]

There are typically one or more outside outlets connected to the GFCI receptacles in the garage, so I would press the test button as this trips the GFCI. Then I would see which other receptacles are not working and unplug any devices on these. I would then reset the GFCI and plug in the devices one at a time to see if any of these are causing the tripping. As noted above the GFCI can easily be replaced, be VERY CAREFUL to install correctly, I have seen several cases of the line and load wires being placed on the wrong terminals resulting in incorrect operation of the GFCI.