Question about tune up nozzle temperature

I have problem to reach and hold the nozzle temperature for ABS print (250 degrees) (fanspeed 60%)
Now i want to tune up the heater. the original is 15V 33W (2.75A )

  • i have buy 12 V 40W - but i think it´s to much for the motherboard because on 15V it go to 63W and 4.2A - it it to much for the motherboard ?