whirlpool FRBB36AF20/2 screen locked

hi guys i have this fridge freezer 4 yrs old we had a power cut last week and i cant unlock the screen , tried everything in the manual compressor fan is humming away but its not getting cold , i had a look a the pcb's today they both look ok , when i disconnect one of the block connectors from the display pcb the alarm triangle goes off and when i was checking continuity at the main pcb when i connected all together again i got the screen to work , but the fan and compressor would not come on so i switched it off and back on again after a few minutes and it as back to being locked again heeellllppp

anyone? have an idea