Try these steps:

1. Reinstall Razer Synapse: Uninstall and reinstall to fix any potential software issues.
2. Check BIOS: Look for any RGB settings in BIOS/UEFI and ensure logo lighting is enabled.
3. Run Windows Update: Make sure all updates are installed after the reinstall.
4. Check Device Manager: Ensure there are no errors related to Razer devices.
5. Reset Lighting Profiles: In Synapse, reset or create a new lighting profile.

For my laptop sent back to Razer for warranty diagnosis/repair, I suspect my laptop’s stiff hinge when opening and closing the laptop slightly flexed the display assembly component leading to the logo lighting going out.  My friend’s Razer laptop opens and closes much more smoothly than mine.  I think that with a enough opening and closing of the laptop lid over the course of months/years, given the hinges are slightly too tight, can result in the logo light eventually breaking/disconnecting.  Note:  I’m careful to open my laptop using the central upper lip to evenly distribute the pressure on the hinges.

Things to test:

• Do you have an option in the BIOS to turn on/off the razer logo lighting?
• Does the lighting equally not work whether you use Synapse 3 or Synapse 4?  Do you go into lighting settings and use the drop-down menu to toggle between ‘static’ or ‘breathing’ as a test?  You must re-select an option for Synapse to talk to the logo light.
• And, does the logo light not work after restoring the Razer Factory Supplied Recovery Image?  Assuming the logo lighting worked when you first purchased the laptop, the light not working after a Razer Image Recovery points the finger at hardware.  In my case, I think the repeated opening/closing of a stiff laptop lid over the course of a year.  It’s the only explanation I can think of other than a BIOS update going wrong resulting in the Synapse driver not being able to send logo light commands to the laptop.

Actually, I’ve gone one better.  To get around the logo not lighting up after sleep problem, I only need to create a single additional profile for the Razer Blade beyond the default profile.  The default profile I have set with the logo static with the additional profile called ‘FPS Gaming’ set to logo breathing.   So to bring the logo light back online I need only flip between the two profiles.
Note:The ‘FPS Gaming’ profile has additional Performance tweaks for when I’m gaming that can cause the laptop to run warmer.  The logo breathing reminds me that the laptop is configured to run warm and needs extra cooling.

I think this logo issue has come about because Razer Laptops traditionally have the logo turned on within the BIOS by default.  In the older Razer laptops, you could change the default setting by booting into the BIOS but the option is not available with my Blade 15 2023.  Now that the logo is off by default, we are dependent upon running Synapse to turn it on and at the mercy of Synapse to manage the logo lighting after the laptop comes out of sleep.
I imagine the default lighting behaviour was changed because of the number of Razer owners who wanted the light off by default to reduce battery drain.  I think Razer decided to turn off the logo by default rather than opening up the option in the BIOS again because they don’t want to encourage users booting into the BIOS.  I really wish Razer didn’t lock down the BIOS so much. 

I have the exact same behaviour with my Razer Blade 15 2023 using Synapse 4.  The logo light is off during boot up.   The logo light will come on once I launch Synapse 4 given my default profile has the logo light set to ‘on’.

Should the logo not come on, I go into Synapse 4, choose lighting tab and click the Logo dropdown menu and then must click on the Static and/or Breathing option in the dropdown.  Using the dropdown menu results in Synapse refreshing the command to light up the logo to the laptop.
Another issue is that if I sleep the laptop, the Razer logo light will turn off then not come back on when I wake the laptop.  I’ve created a work-around by creating two additional Synapse profiles for my Blade, one with the Razer Logo breathing, the other with the Logo static.  Switching between the profiles kicks the logo back into life.
To make it easy to switch between the profiles, I created a Synapse Razer Huntsman Mini inter-device macro to cycle between Razer profiles when I press Hypershift+F.
So, when my laptop comes out of sleep, I can easily bring the logo light back to life by pressing Hypershift+F a few times as switching between profiles causes Synapse to refresh the logo lighting setting to the laptop.

Note:  I devised this work-around using my friend’s Razer Blade 15 2023 lent to me.  My laptop which is the exact same model is going through Razer RMA because the logo light refuses to turn on regardless of what I do.  Once I get my own laptop back from Razer I will test it to see if it exhibits the same behaviour.

what…. I hope someone see this post and fix it well….

At least you can reactivate, I can’t , I don’t know if it’s hardware or software anymore

me too have the same issue , always reboot on razer blade 18 the logo light always off automatically, need to open synapse to choose logo light off and on to re-active….

Also having the same issues after a windows update I did. Back logo is not lighting anymore and it came on one time temporarily on its own. But it stopped same day, we need help with this.