HP ENVY Photo 7855 printer will not turn on at all

[Derek210]

The printer won't turn on at all. Like it just won't turn on.

I can confirm the power supply unit and the power cords have the proper voltage reading when testing them out with the multimeter, as well I open up the printer to ensure the motherboard all those plugging are plug in properly.

I've tested all of those 30 seconds power button hold, unplugged over an hour, and while unplugged to hold the power button for 30 seconds all of those trouble shooting, nothing works.

(The only thing that is on are the tiny yellow light for the ethernet plug in the back and the tiny white light for the USB plug in the front when the printer is plugged in, nothing else is turned on besides those two things.)

[Max3Aj]

@Derek210, Hello and welcome to the HP Support Community!

Thanks for posting your question. I'm here to help you get things back on track.

I understand how frustrating it can be when your HP ENVY Photo 7855 won’t power on, especially after trying multiple troubleshooting steps. You've already done a great job checking the power supply, cables, and internal connections. Since the Ethernet and USB port lights are on, it indicates that the printer is receiving some power, but the mainboard may not be initializing properly.

Let’s go through a few more advanced steps to isolate the issue:

Confirm Power Supply Health

Even though you've tested the voltage, please ensure the power adapter is the original HP adapter and not a third-party replacement. HP printers are sensitive to voltage fluctuations and third-party adapters may not deliver the correct wattage.

Perform a Hard Reset (One More Time)

Sometimes a reset works after a few tries. Please try this sequence exactly:

1. Unplug the power cord from the wall and the printer.
2. Wait at least 60 seconds.
3. While unplugged, press and hold the Power button for 30 seconds.
4. Plug the power cord directly into a wall outlet (avoid surge protectors).
5. Reconnect the power cord to the printer and try turning it on.

Check for Signs of Life

Since the Ethernet and USB lights are on:

• Try connecting the printer to your PC via USB.
• Open Device Manager on your Windows 11 PC and check if the printer is detected under Universal Serial Bus Controllers or Printers.
• If detected, this could indicate a partial board failure (e.g., display or power logic board).

Internal Hardware Check (Advanced)

Since you've already opened the printer:

• Double-check the power button ribbon cable connection to the logic board.
• Inspect the mainboard for any burnt components, bulging capacitors, or corrosion.
• If you have access to a thermal camera or IR thermometer, check if any components are heating up abnormally when plugged in.

If none of the above steps work, the issue is likely with the main logic board or power management IC. In that case, we suggest you please visit the nearest HP authorized service center, the service team will check and assist you. 
Kindly follow this link to locate the nearest HP service center: HP® Service Center Locator - United States | HP® Support
(Select the country from the dropdown menu and enter the city name or pincode)

I hope the information shared has been useful and resolves your concern.

Wishing you a smooth and hassle-free experience ahead!

If this solution helped, please click “Accepted Solution” so others can benefit too. Don’t forget to hit the “Yes” button if you found this helpful!

Warm regards,

Max3Aj

HP Support