Question edited for clarity and toss in some CAPS
Unplug it for a couple of hours. Press and Hold the On button for 2 minutes and plug it back in. That _should_ make it lose its memory by dissipating all internal energy.
It seems you have done all the troubleshooting yourself. You can't do a full factory reset, because you can't see the screen. You either have an internal power supply unit failure or a control board failure. Neither are really home repairs. A new one is $147, or you can take it to an HP Service Centre. I am sure not to answer you wanted but it has failed.
Here is a Troubleshooting Manual. HP always do things in style! Low-voltage power supply on Page 34.
Laser Pros Internationalhttps://www.laserpros.com > img > hp-manuals
If the hardware or software configuration has not changed or the problem is not associated with any specific software, see the complete service manual for this ...
166 pages
Here is the Service Manual. It looks like the power supply PCB is behind the button. The main PCB is on the right side above the cassette.
Question edited for clarity.
'OfficeJet Pro', is a series of about 40 printers and you give no clue which one you have!
Here are the Service Manual suppliers.
https://www.google.com/search?q=HP+Officejet+Pro+Printer+Service+Manual
The search query for this is
HP OfficeJet Pro (model) service manual
..
Download the latest drivers, firmware, and software for your HP ENVY 5055 ... How to Set Up a Wireless HP Printer Using HP Smart in Windows 10 Learn how to ...
HP Envy 5055 Wireless Setup For Windows Open the Control Panel Settings menu on the printer after turning it on. Shift downwards and select the Wireless Settings option. Touch the HP Envy 5055 wireless Setup Wizard option and halt for a few seconds. The Setup Wizard turns on the printer's Wi-Fi.
The error code "22.0;10" on an HP DesignJet T610 44-inch printer indicates a problem with the printer's ink supply station. Specifically, it suggests an issue with the Ink Supply Tubes System.
The error code 90020503 on an HP Deskjet 960C Series printer typically indicates a paper jam or an issue with the paper feed mechanism. Here are some steps you can take to resolve the error:
Check for paper jams: Open the printer's access doors and carefully remove any jammed paper. Make sure to check all areas of the printer, including the input and output trays, as well as the rear access panel.
Clear any obstructions: Look for any foreign objects or debris that may be blocking the paper path or causing the error. Gently remove any obstructions that you find.
Reset the printer: Turn off the printer, unplug it from the power source, and wait for a few minutes. Then, plug it back in and turn it on. This will perform a power cycle, which can often resolve temporary issues.
Check paper condition: Ensure that the paper you are using is not wrinkled, folded, or damaged. Straighten out any curled edges and make sure the paper is properly aligned in the tray.
Adjust paper guides: Verify that the paper guides in the input tray are adjusted correctly to fit the size of the paper being used. Improperly adjusted paper guides can cause paper jams or feeding issues.
Clean the paper feed rollers: Over time, paper dust and debris can accumulate on the paper feed rollers, causing them to slip and result in paper feed problems. Clean the rollers using a lint-free cloth lightly dampened with water or isopropyl alcohol.
To obtain a wiring schematic or service repair manual for the HP Officejet Pro L7780 Printer, I recommend reaching out to HP directly. You can visit the HP Support website and navigate to the product support page for the L7780 printer model. There, you should be able to find relevant documentation, including service manuals or wiring schematics, that can assist you with your specific needs. HP's official support channels are the most reliable sources for obtaining accurate and up-to-date information for their products.
These videos might help
The blue shadow problem you're experiencing with your HP Scanjet G2710 scanner could be caused by various factors, including issues with the scanner hardware or settings. Here are some steps you can take to troubleshoot and potentially fix the problem:
1. Clean the Scanner Glass: Start by cleaning the scanner glass thoroughly. Use a lint-free cloth and a mild glass cleaner to remove any dirt, smudges, or debris that may be affecting the scanning process. Make sure to clean both the main glass and the small strip of glass used for scanning smaller items.
2. Check Scanner Settings: Ensure that the scanner settings are configured correctly. Open the scanning software on your computer and verify that the color settings, resolution, and scan area are appropriate for your needs. Adjusting these settings might help alleviate the blue shadow issue.
3. Update Scanner Drivers: Visit the HP support website and check for any available driver updates for your Scanjet G2710 scanner. Download and install the latest drivers to ensure compatibility and optimal performance. Outdated drivers can sometimes cause scanning issues.
4. Test with Different Software: Try scanning with different scanning software to determine if the issue is specific to a particular program. If the problem persists across multiple software applications, it is more likely a hardware issue.
5. Check the Flat Cable: Inspect the flat cable that connects the scanner head to the scanner motherboard. Look for any visible signs of damage, such as cuts, fraying, or loose connections. If the cable appears to be damaged, it may need to be replaced. Contact the manufacturer or a qualified technician for assistance with replacing the cable.
6. Contact Manufacturer Support: If the issue persists after trying the above steps, it's recommended to contact HP customer support for further assistance. They can provide you with specific troubleshooting guidance or advise on any necessary repairs or replacements.
When contacting support, make sure to provide them with detailed information about the problem, the steps you have already taken to troubleshoot, and any error messages or patterns you have noticed. This will help them diagnose and resolve the issue more effectively.
Try uninstalling your PDF program, reboot and reinstall the latest version. It may be the way it is parsing the colours, if the Printer Test Page printed okay.
Unplug machine for awhile then plugback. It may reboot..remember its a computer n needs dailyrest. Also any connecting plugs on machine shud b done the same....debris gits on the pins causin bad contact. Make sure fan is workn rite
