Re: tilt&trim
Check on the engine for solenoids/relays there should be one for each direction up and down. Mine are in a black box on the back of my 90 HP Evinrude between the heads. Swap them and see if it is the relay before looking at the switch. If you swap relays and the motor now lowers and won't raise you need to remove the relays one at a time and find the good one. If you have a meter and some help you can check at the relay for power when the switch get depressed this will let you know if the switch is working. Good Luck.