What part is this?

[OutThere]

it's from the PFC part of a switch mode power supply. it is across an inductor. the part number is SG7004 . I was thinking it's a Zenor diode, the silk screen part shows a box with a "G" inside. I used on a dvm the diode test , the display just stayed at open loop. i used one of those parts testers with a small LCD, said bad part , unknown part'

[coromonadalix]

gas tube discharge maybe ?

[boB]

Can you measure it ?   Diode drop ?  Resistance ?

If low resistance, it might be a fuse

[fzabkar]

Spark Gap

https://brightking.yageo.com/PRODUCTS/list_123.aspx?lcid=52

https://brightking.yageo.com/uploadfiles/file/SPG/2021031418221622161050.pdf

https://www.unictron.com/protection/circuit-protection-components/spark-gap-protectors-spg/

[OutThere]

please  R E A D my post

[OutThere]

thank you  for the info   

[tooki]

please  R E A D my post

Please learn to use the “quote” button so people know what you’re responding to. “Reply” simply adds a new reply to the end of the thread, with no further context or ability to show what it was in response to.