The keyword here is "5 minutes", is it really like exactly 5 mins or is it random?
You always resolder the mouse/joystick ports whenever you open up the keyboard because of the wear and tear these ports are subjected to, not so much that they were badly soldered from the beginning... after some use, a loose contact is more or less guaranteed.
Other than the mouse/joystick port needing resoldering the keyboard is in my experience very resilient.https://www.dev-docs.org/docs/
got a Mega ST schematic "Atari Mega ST2/ST4 Schematic (Rev 9, C100166)", page 8 & 9 contain a schematic of the keyboard (the same is used on all st/ste/tt/f030).
as you can see, the signals from the joystick port pass through a line filter, then have a 10k Ohm pull-up resistor, and after that the mouse/firebuttons are connected straight to the IKBD. Obviously reseating socketed chips never hurts.