• If the switch power supply does not light up, troubleshoot as per "Switch power supply indicator not lighting up>>".
• If the power supply indicator does light up, but the output voltage is lower than normal,

1. Remove all the loads on the power supply. If the power supply output voltage returns to normal, one of the loads is faulty and causes a short circuit.

• Plug back all the loads one by one to sort out the faulty one(s).
• Replace the faulty one(s) with identical equivalents.

      2.  If step 1 has failed and the mainboard stands dubious, see "Mainboard causing the laser power voltage to drop>>" to troubleshoot.

      3.  If all loads and the mainboard have been ruled out as faulty but the low-voltage power supply still reads a voltage lower than it should, replace the low-voltage power supply with a new, identical one.