error message says "The printhead appears to be missing, not detected, or incorrectly installed."

[MikeEnders]

After I saw I message, I removed the assembly that has the printer cartridges and printhead.  I cleaned the printhead with rubbing alcohol as reinstalled the assembly.  The error persists.

[A_Gayathri · Accepted solution]

Hi @MikeEnders,

Welcome to the HP Support Community

I understand you are facing an issue with your HP OfficeJet Pro 7740 Wide Format All-In-One Printer. Not to worry I will help you to get a resolution to resolve the issue.

Let's perform a power drain: 

• With the printer turned on, disconnect the power cord from the rear of the printer and also unplug the power cord from the wall outlet.
• Remove the USB cable, if present.
• Wait for 2-3 minutes, press and hold the power button on your printer for about 30 seconds to remove any additional charge.
• Now plug back the power cable straight to a wall outlet without any surge protector or an extension cord (This is important) and then plug back the power cord to the printer.
• Turn on the printer and wait till the warm-up period finishes and the printer is idle

Update the printer firmware 

• Click here to download and install the latest printer firmware from your product
• Click here to know different methods of updating the printer firmware.

If the issue persists, then please follow the steps mentioned in this document: HP OfficeJet 7740, 8210, 8700 Printers - Replacing the Printhead

Hope this helps! Keep me posted. 

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping!

[MikeEnders]

Unplugging the printer and plugging it back in again solved the problem

[A_Gayathri]

@MikeEnders,

That's great! Happy to hear that the issue has been resolved. If you need further assistance feel free to reach out to us. 

If the information I've provided was helpful, give us some reinforcement by clicking the Accept as Solution and Kudos, Thumbs Up buttons on the public post, that'll help us and others see that we've got the answers!

Have a great day ahead!