In the afternoon, the TWIN excimer amplifier suddenly stopped firing after running for half hour. I found the power supply light became red, the light was off after pressing the reset button. Then I pushed the H.V. button and Laser button, I heard a buzz sound inside the excimer chamber. I energized gradually to the amplifier, the voltage reached 12 kV, the buzz appeared again then the system shut down immediately.
I opened the chamber, and turn on the system to check where the buzz came from. I found the high voltage cable was burn, the buzz was from the broken cable. The arcing from the cable caused the fail in high voltage increasement.