Replacing the laser tube

New K40. Had arcing and tube wouldn’t fire. Company sent me a new tube. The existing setup has a ballast resistor? on the current setup. The tube they sent has wires attached but doesn’t include the ballast. My question is: do I splice into the ballast and keep that setup with the new tube? Or splice into the wire to the power supply (or wire to the power supply)? I bought some HV tape and intend to solder the connection. Input appreciated.

Post a picture of the LPS.
The old supplies used to have ballasts I do not think the new ones need them.
Did you ask the vendor if you need the balast?

I would not use tape but rather RTV. I believe there are instructions under the K40 Intro tab.

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That would be at Where can I find K40 replacement parts?

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That should not need a ballast can you show me where it is wired in the circuit.

That’s a ceramic sleeve/cap which is used for insulation.

If your new tube is also pre-wired, you can reuse it. You just push the joint into it and fix the wires with some electrical tape in place.


I was able to get a couple of shots without removing the PS. I also have an email into the vendor.

From the vendor:

New message from: acautoparts04 (84,625PURPLE_SHOOTING_STAR Star)
Dear Customer,

Thanks for getting back to us.
You can use the old ballast to secure the high-voltage wire.
Here is an instruction video of how to install the laser tube for your reference:

We hope this helps.
Should you need further assistance, please do not hesitate to let us know.

But, it’s not a ballast. Says so in the video… “ceramic block” for electrical insulation.


I don’t buy that that ceramic connector and electrical tape is HV secure! I would expect it to leak out the open end of the ceramic connector. But that is just me!

I would take the ceramic connector assy and pot it with RTV. You can do this by pushing the wire into the ceramic and then slide a tube filled with RTV over it. Then fill any voids in the tube.

Alternately use a HV connector.


So I finished installing the new tube today. As stated, the ceramic block is not a ballast but only a ceramic cap to go over the wire connection which I soldered and then wrapped with HV self-fusing tape. Works fine now. Thanks for all the inputs!