Nozzle heating stopping at 150°

[StridAst]

Any suggestions for what to check to fix incomplete heating? My printer is only heating up to around 150 or so and it's just stopping there. I've tried changing both the heater and thermistor. No luck, the problem continues. Changing the target temp doesn't affect when it stops heating up.

[TommyDee]

Insufficient power? Try turning off the heated bed, if any. If you can, monitor the voltage at the heater's power pins (as close to the heater as possible) to see if it is seriously low from what's expected.