How to Test a Neon Transformer

Written by paul lin
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to Test a Neon Transformer
"Open" signs are made up of neon tubing and a neon transformer. (Neon Open sign 2 image by Edward Stephens from

Neon transformers are used to light neon signs that are great for attracting customers to businesses. These "Open" signs are powered by constant electrical current that pass through the transformers. Since neon tubing produces an array of coloured lights, noticing damages of flickering lights and replacing the neon tubing is simple. Because most of the issues occurs with the neon tubing, testing a neon transformer to reconfirm the damage is not within the transformer is important.

Skill level:
Moderately Easy

Things you need

  • Screwdriver
  • Replacement neon tubes

Show MoreHide


  1. 1

    Power on the neon transformer. Observe signs of initial neon flickering of the neon source or other initial flickering during the warming up of neon gas. If the neon transformer light continues to flicker, the neon substance in the transformer could be worn out.

  2. 2

    Plug the neon transformer into different outlets to rule out possible electrical socket problems. The outlet needs to provide clean and steady current to insure the neon transformer is receiving consistent electrical currents.

  3. 3

    Remove the neon inside the transformer. Neon is generally kept in tubes that attach to the transformer to give it the electrical current it needs to light up. You may need to use a screwdriver to remove the clamps that hold the neon tubes in place. Replace the tube with a fresh neon tube. If it works, the problem does not lie within the transformer, but the neon itself. If the new neon tube does not light, the transformer will need to be repaired or replaced.

Tips and warnings

  • Handle neon transformers with care. Neon sign transformers have an output electrical current between 4000 and 12000 volts. Always turn off and unplug your neon transformers as you change out the neon tubes.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.