Comment by Retr0id

YouTube. Pick any piece of consumer electronics and you'll find videos of people diagnosing and repairing it, at both hobbyist and pro-repair-shop level.

The Nintendo Switch Lite is a fun piece of hardware because they're cheap to buy used/broken and there are many opportunities for component-level repair.

Some great written info (specific to the switch) here:

https://www.retrosix.wiki/first-stage-boot-short-checks

https://repair.wiki/w/Nintendo_Switch