Garmin Forerunner 405 died and will not turn on
No matter how hard you press the power button nothing happens
AC adaptor reset
Many power issues with the Garmin can be fixed by resetting the AC adaptor. Unplug the AC adaptor from the outlet and the watch. Plug the AC adaptor into a wall outlet and then clip the watch onto the charging clip.
Bad wall outlet
It is possible that the wall outlet is bad. Plug another device into the outlet to see if it is bad. If it is, find another outlet. Check if the outlet is controlled by a wall switch. If it is, turn it on.
If the cables and outlets are not the problem, check the charging contacts on the watch. If there is corrosion on the contacts, view the Contact cleaning guide. If the watch does not charge now, replace the battery.
Watch does not respond
"Watch does not respond to button pushing or touchscreen"
Grease and sweat will decrease sensitivity on touchscreen. Clean screen with isopropyl alcohol and paper towel. The isopropyl alcohol will sanitize the screen from debris along with restoring full functionality of the watch.
Springs behind the two external buttons may be corroded. Open watch and replace springs. Refer to the button replacement guide.
The touchscreen can malfunction. Open the watch and replace touchscreen module.
Moisture behind screen
"The screen looks foggy and distorted"
Moisture may get into the watch. Open the watch and inspect rubber o-ring for tears. If tears are present, replace rubber o-ring.
If water is coming into the watch apply silicone sealant on the o-ring.
"The screen froze mid-workout and will not unfreeze"
Perform a reset on the watch by holding the two external button for five seconds.
" The glue has melted, which holds the display in place."
In extreme temperatures, the glue may melt causing the display to detach. This calls for a new display. To replace the display, first openthe watch. While the watch is in two pieces, replace the face of the watch.