Hello, i7 X230 motherboard was shorted with bad cooler fan. Previous owner tried use fan from another machine. New original fan is working OK, but from this time is picture only on external monitor. Own lcd have backlight only and no picture. Also sound card is not working. Clean ME trick don't help.
I check all fuses and they are OK. Can somebody help me what can be bad? I have some broken mobos for parts.

The only thing that is fused is the backlight and if that works, not a fuse problem. Check the LCD cable for damage or cracks where it connects to the motherboard. Clean the connector. It could have been damaged when motherboard was taken out to get to the fan.