first powerup and it turns off after a few seconds
I just finished assembly. After turning it on the LCD lights up flickers the fan starts. The LCD then is solid and then fan goes but after 4-5 seconds it stops. If I leave the switch on it has started again a couple of times but always stops after a few seconds. If I insert the SD card it doesn't start at all? Please any suggestions
Re: first powerup and it turns off after a few seconds
Check filament sensor plug positions - or just unplug the sensor at the Extruder and try powering up.
Re: first powerup and it turns off after a few seconds
I had similar symptoms. I found that I had not properly seated the black and white 'Power Panic' connector. when seated properly, the problem vanished.
RE: first powerup and it turns off after a few seconds
I had a similar problem. I double checked connection and I had placed the filament sensor plug on the upper row of pins.
Problem continued even after correcting the cable connection!
Problem solved when I uploaded the previous firmware. Previous to the latest prusa3d_fw_MK3S_3_8_1_2869,
which is the prusa3d_fw_MK3S_3_8_1_2869.hex ( a folder with the firmware for the mmu2s as well).
I suspect after having done such a mistake, you might have to re-upload the firmware.