Solving High Voltage Power Supply Failure Problems

High Voltage power supplies have several benefits and work effectively for industrial applications. However, there can be drawbacks to HV power supplies. For instance, electronic components can fail due to high voltages, which results in overheating. The damage can be irreversible as it adds up over time. Once the electronic components experience failure, the HV power supply will ultimately fail. High voltages can cause fatal injuries and, as such, must be solved correctly and by a professional.

23 lbs of trouble! Each Kaiser LS402 high voltage power supply weighs 23 lbs, and each one we have received for repairs has had different, nearly catastrophic failures…including components blown beyond recognition (see pics). 

The problems causing this damage have varied and include:

  • Internal voltage regulator failure
  • Failure of the HV output coils
  • Failure of the HV, High-Frequency output filter capacitors
  • Failure of the internal switching power supply that set up the 24 VDC output for the Voltage regulators and the bus voltage circuit 
Kaiser ls402 Power supply Damage

So why might you have trouble with this high-voltage power supply? As in the case of our Midwest US laser technology customer, the reasons vary according to the age, condition, usage, and maintenance schedule for each unit.   For example, all capacitors wear out over time and usage. How do you prevent high-voltage power supply failures? Preventive maintenance service, which would include replacing aging capacitors, would help lengthen the life of the power supplies.

Maintaining High Voltage Power Supplies

High Voltage power lines

Cleaning switch gears can help in preventing HV power supply failures. Debris, moisture, and dust collected on the switch gears can deteriorate the protective devices and the insulation. The cleaning should be done in addition to other maintenance work like lubrication, tightening, and general inspection. Cleaning the control circuit should also be done with appropriate cleaning agents. Additionally, the circuit board can be repaired if any damage is noticed during the inspection. 

A regular inspection would also help identify potential problems before they worsen. If there are damages to parts of the power supply equipment, they should be replaced or repaired depending on the level of damage

It is also essential to keep track of the oil levels as regularly as possible. The oil level in the magnetic oil gauge should always be correct. Leakages should also be sealed immediately. 

Having the electrolytic capacitors (not just the HV HF) replaced periodically will help prevent serious damage in the long run. You should determine the frequency of this type of maintenance based on whether the machine often sits idle or if it is used frequently. Have your HV power supply serviced at least every 3-4 years if it gets frequent use.

Are you hearing weird squealing sounds or resonance at high frequency? Warning! Catastrophic failure of your unit could be close at hand! If, during use, you notice any unusual voltage levels or odd sounds or the unit begins to resonate, consider this a warning that your machine is in trouble and needs service. Take it offline immediately and send it in for service before the damage is unrepairable.

Power supply repairs are usually far less than purchasing a new one, especially high voltage power supplies typically used for laser technology, such as the Kaiser LS402 pictured. Having a test fixture on-site at the repair center was invaluable, allowing the service team to test each of these Kaiser LS402 power supplies with the actual load condition it would face in use as it fires the laser.

Test fixtures like this are comprised of components used in the actual laser application and allow the technicians to confirm that the power supply is fully repaired and operational under load before returning it to the customer.

The test fixture can include operation at low, medium, and high voltage output based on the acceptable power supply range. 

The test fixture can also be used to:

  • Make accurate HV in-line measurements
  • View and measure AC ripple & noise on DC HV
  • Measure absolute HV DC to 0.25% @ 25 PPM stability
  • View and measure Trise, Tfall, overshoot & settling time
  • Measure & monitor signals from 35Hz to 10MHz
  • View signals from DC to 20MHz 

If you are searching for a repair center for your damaged power supplies or other industrial electronics, check first to see if your equipment is still under warranty. If so, contact the OEM about repairs. If it is out of warranty, contact an independent industrial electronic repair center to find out if they are a good fit for your company and your particular repair needs.

They should offer free evaluations for your damaged equipment and if needed, a free quote for repairs (no bench fees!). They should also provide repair reports if requested and a good warranty of at least one year covering parts and labor.

Contact ACS Industrial Services for All Your Industrial Repair Needs

ACS Industrial Services is an independent industrial electronic repair center providing repairs for all types of industrial electronic equipment and most all manufacturers, including power supply repairs, circuit boards, drives, servo motors, CNC equipment, encoders, monitors and touchscreens, test equipment, and much more. 

Rush Service is available, and 2-Year Warranties cover most repairs. The customer service team can answer your questions and help solve your industrial electronic repair problems. You can reach them by calling 800-605-6419 or going to