Power supply problem

a) The switch trip：
i. You connected Positive and negative pole wrongly and caused short circuit, need to check the wiring
b) NO output：
i. You need to change a new power supply。
c) There is big noise in power supply.
i. Check the power supply, fan, heating rods, make sure they are all with 24V, if the fan and heating rods are with 12V, then you need to change these parts, if they are 24V, then you need to change the power supply.
d) The power supply was burned ：
i. You need to replace the power supply