thermal errors driving me crazy  

thermal errors driving me crazy

hey guys i wonder if you could help i'm getting some annoying errors that i can't seem to fix on my MK3S+, i was getting thermal runaway so i changed my hotend thermistor still happening so i changed my hotend heater fixed it brifely then the part fan died so i replaced it then drives gears start clicking and under exturding printed new idler door and getting thermal runaway again, replaced bed thermistor and made new wire loom to bed still happening it just stops heating so i thought maybe power supply replaced that still thermal runaway i'm stumped oh and i getting random power panic errors as well

so i have replaced:

hotend thermistor

bed thermistor

heater cartridge

wires to bed ,heater and both thermistors

power supply

part cooling fan

and i have factory reset multiple times as well as downgraded firmware

anyone got any ideas