SERVICE NOTE KRYPTON ARC LAMP REPLACEMENT S/N: 8111001

BACKGROUND

Reports have been received from a number of customers reguarding the following problems after replaced krypton arc lamps in their KY-5 laser heads:

1. Lamps will not fire.
2. No output from laser.
3. Short lamp life.

The high power krypton arc lamps must be properly connected to the power supply + and - wires and to the cooling system to prevent the above used problems.

NOTE:

The higher power krypton arc lamps have a specially constructed anode (+) terminal. The anode (+) terminal has an internal cooling channel. The anode (+) terminal is the spherical electrode in the tube. The cathode (-) terminal is pointed. It is easy to install a lamp assembly backwards in the laser cavity. Once installed in the laser cavity it is not possible to varify polarity without removing the upper laser cavity block.

If the lamps are not properly connected in series(- to -) the lamps may not fire.
If the lamps are properly connected in series but the power connections are reversed the arc (if they fire) may be very unstable and will not properly pump the laser causing low or no output. This reversed connection will also cause premature lamp failure.
The coolant pump must provide pressurized coolant to the lamp anodes only or the lamps will be subject to premature failure.

WARNING:

Improper lamp cooling, as indicated above, can cause serious dammage to the cavity reflector surface.

RECOMMENDATION

1. After properly installing a krypton arc lamp in its flow tube (following Compulaser instructions and using the Compulaser lamp insertion tool) visually inspect the assembly as follows:
A) The lamo electrodes are not blocking the fluid flow holes behind the finger stock clips.
B) The Spherical electrode (anode) head coolant flow hole is unobstructed.

2. Before installing the lamp assembly in the cavity, locate the anode(+) end of the lamp (hemespheric electrode) and mark the flow tube clamping nut with a red mark (felt pen ot paint dot).WARNING: do not allow any marks to get into the flowtube.

3. Install the lamps in the cavity such that the anode(+) end of onelamp is adjacent to the power supply lead and the cathode (-) end of the other lamp is adjacent to the power supply lead in the laser head.

4. Varify that coolant flow from the pump goes directly only to anode (+) lamp terminal ends.
NOTE: Coolant flow from the cathode (-) lamp terminals will be routed to the upper or lower cavity reflector block before it leaves the laser head.

5. Complete all electrical connections.

6. Test connections for leaks by brefly turning on the cooler and watching all fluid connections in the laser head and repair as necessary.

7. The system is now ready to restart.

NOTE: Proper firing of the lamps may be difficult or impossible due to carbon on the laser cavity nylon and teflon end insulators. The carbon buildup can be caused by excessive heat or arking of the lamps due to contaminated deionized water or dirt on the insulators. When changing lamps inspect the insulators carefully and prepare as required.