Omen won't turn on - no lights, no sound

[POLY1]

I removed the casing to get the PN of one of the fans because the fan had stopped working, so I ordered a new fan with the PN. Then when I put the casing back on the laptop didn't turn on anymore.

I have tried the general troubleshooting techniques: remove power lead and battery, hold power button for 1 minute, reconnect both; then again but only reconnecting the battery; then again but only reconnecting the power lead.
Each time nothing happens - unlike other articles I had read for a similar problem I don't even get lights or fans, its as if somehow detached from all power.

I have followed a few YouTube tutorial trying to reset BIOS but that doesn't work either - no response.

I have come to the conclusion that I may have displaced something when removing the case but I don't know what I'm looking for to put back in.
In was working fine before that so I am inclined to think that it is the removal of the case and one of the fans that has caused this and not coincidence.

Any help appreciated.

[Echo_Lake]

@POLY1

Thank you for posting on the HP Support Community.

Don't worry as I'll be glad to help, As we have limited support boundaries in the support community as of now.

I would request you to contact our Support and our Support Engineers should be able to sort this out. HP Support can be reached by clicking on the following link: www.hp.com/contacthp/

Please feel free to contact us here anytime you need any further assistance. Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.