How can i disable deep sleep mode on brother hl printer

there is no sleep mode. set up is done under printers. You will need the Cd that comes with printer.
Call Brother for one.

https://download.brother.com/welcome/doc002308/cv_hl2140_usaeng_usr_d.pdf

To turn off the sleep mode of your brother machine, at first, you need to press the "Start" and "Options" keys at the same time. When the LCDs the message saying "Sleep Mode: On", press the "Up" or "Down" arrow keys to turn it off. In the end, press the "OK" button followed by Stop/Exit.
https://www.brother-support.us/how-to-wake-up-brother-printer-from-deep-sleep/

It should "wake up" when you tell it to print.. Wait a minute or two and see if it prints.

I am a Brother employee working for the software technical support department.

We have a solution for your printing issue posted on our solution site.

http://www.brother-usa.com/FAQs/Solution.aspx?FAQID=200000032479

Description of Problem 100000025364
How do I perform a firmware update or firmware upgrade on my Brother machine?

Brother Software Technical Support
http://www.brother-usa.com

HI Lan,
Go To Below official Brother Printer Solution Page For Your problem, The printer will not turn on Brother Still having Problem Then follow Us For Brother Printer Support

This may help some (22Jun2022): MFC-9840CDW using wi-fi option to connect, currently running on Windows 11 and for a long while, years even Windows 10, I too was constantly having a problem of this machine going into sleep mode and not coming out when wanting to print, the driver/firmware is the latest from the brother's support site for this model. The actual printer machine: no status light, says "Sleep" and the "menu key button" does not respond (need this key to respond). The PC, the brother printer icon does show in the control panel but do not have the "set as default printer" option. I assume in sleep or deep mode the PC does not see the actual printing device. In my case, Brother PC-Fax v.2.1 was selected and I could still scan a document to my PC. Fix action (need to turn off sleep mode on the printer itself): turn off printer (maybe wait 5 min, probably don't have to wait). turn printer back on, it cycles itself the status light on the printer should be green, at this point the printer should work as normal. But you should immediately turn off "sleep mode" because once it goes into sleep mode it no longer responds. Press the "Menu" key, enter "general setup" press "OK" button, arrow down to "ecology" (6) press "OK" button, select "Sleep Time" enter 000, press "OK" should respond with "accepted". After I did this, I currently have no status light and it still says "sleep" just like before. I just did this and it's been a couple of hours and I can print a test page whereas before I could not. And the icon in the control panel is as it should be, a check mark showing its the default printer. Hopefully, this is a permanent fix at least until I replace this printer.

press go button 2 times ,printer and computer is not connected properly .

I found this from Tony Benjamin
I have tested it on two different Brother Lasers and it worked.

To cancel DEEP SLEEP on Brother Printer

1. Go to General Setup then OK
2. Ecology then OK
3. SLEEP TIME then OK
4. While sleep time is display push Down Arrow and CANCEL at the same time!
5. DEEP SLEEP on/off toggle by Arrow keys
6. OK to SAVE Deep Sleep off.

It is a shame they don't have this in the web interface or manual they sent with the printer.

Hi Go to the Setup mode and disable the sleep mode.

It sounds like you have some serious wiring issues within the building / house you are in, and voltage is being sent back through ground when the printers fuser goes into warm-up.

A line conditioner / stabilizer may help, but honestly, I would call an electrician before it completely shorts out the computer, or burns the house down.