connecting heater shows all low, disconnects resolves

[egypro98]

I have an issue with my skr2 revB I was working with the regular hot end heater (red one) for months, two weeks ago i switched to 50w ceramic heater today when i was printing like regular the screen peepa and ahowed e1 failed printer halted, when i restarted the printer it peeps a lot and shows drivers backwards, all low and the fans all off after many searhing and problem tracking, that what i found: 1-diconnecting the heater solves the problem 2-heater and the thermistor are perfect after testing on another board 3-heater socket reads 12.8 volts as the power supply when the heater is disconnected 4-datasheet inducates that 10a hot end is the max so 4 amps of 50w should be no problem 5-datasheet talked about extra safety on heater pins my conclusions are as: 1-mosfet is stuck as closed 2-board triggers that mosfet as on and turns off the board for safety 3-the remaining problems are as a result from disconnected power 4-datasheet is not honest about that 10a heater current (4a damages the mosfet) links to problems like mine https://www.reddit.com/.../max_heater_current_12v_on_skr.../ https://www.reddit.com/.../skr_14_turbo_24v_with_50w.../ my question are 1-Is that a faulty mosfet? 2-how can i fix or replace the mosfet? 3-why the problem happened?

[hcet14]

1-Yes it's no high quality part 2-You may look here https://github.com/bigtreetech/SKR-2/issues/102#issuecomment-1053588361 3-well, same as 1