"Unable to Communicate with Scanner" about 50% of the time with HP Envy 7855, Windows7, Wireless

[SherylA]

Hello.  I have recently installed the 7855.  Scanning is touchy, at best.  Half the time I try to run the scan software and get the message "Unable to Communicate with Scanner."  I run HP Print and Scan Doctor, which tells me that everything is fine, but even then, sometimes when I run the Test Scan it works, and sometimes it gets the message Unable to Communicate with Scanner.  Is there any way to fix this problem?  Is it related to my firewall, perhaps?

[Riddle_Decipher]

@SherylA here's how you do it:

Step 1: Reset the printer and check the power source

Reset the printer to clear certain error states by calibrating the scanner mechanism, and then check the power source to confirm the printer is getting enough power to operate the scanner.

1. Press the Power button to turn on the printer, if it is not already on.

2. With the printer turned on, disconnect the power cord from the printer.

3. Disconnect the power cord from the power source, and then wait 30 seconds.

4. If you previously connected the power cord to a power strip or multi-plug outlet adapter, reconnect the cord directly to a wall outlet to ensure the printer is getting enough power.

5. Reconnect the power cord to the rear of the printer, and then turn on the printer.

   • If the error no longer displays, make a test copy to confirm the issue is resolved.

   • If the error still displays, connect the printer power cord to a different wall outlet to determine if the original outlet is causing the issue.

   • If the error still displays with a different wall outlet, continue to the next step.

Step 2: Run the Print and Scan Doctor (Windows only)

Some scan error states might be resolved by running this automated troubleshooting tool for Windows computers.

1. Go to HP Print and Scan Doctor to download and install the tool.

2. Click Start on the Welcome screen, click your printer name, and then click Next to continue to the Finding and Fixing Problems screen.

3. Click Fix Scanning, and then follow any on-screen instructions to resolve the issue.

   • If the error no longer displays, make a test copy to confirm the issue is resolved.

   • If the error still displays, continue to the next step.

Step 3: Check the scanner bar functionality

Perform a visual test of the scanner mechanism to see if it is jammed.

1. Remove any original documents or photos from the scanner glass.

2. Lift the scanner lid slightly, and then press the Copy button or icon.

   • If the scanner light does not move, the scanner mechanism is likely jammed. Contact HP to service the printer.

   • If the scanner light moves but the error still displays, continue to the next section.

Additional troubleshooting

Depending on your printer model, one or more of the following tasks might resolve the scanner issue.

• Reinstall the printer software: Uninstall the existing printer software and driver, and then install the latest version from HP Software and Driver Downloads.

• Restore factory default settings: For printers with touchscreen or menu-based control panels, locate the Restore Factory Defaults or similar menu under the Setup or Tools menu.

Upgrade the printer firmware using the steps mentioned in this link: Click here

P.S: Welcome to HP Community 😉

Keep me posted, as I (Or a trusted colleague) shall follow-up on this case to ensure the concern has been addressed, 

And your device is up and running again, only in case you don't get back to us, first! 

That said, If the information I've provided was helpful, give us some reinforcement by clicking the solution and kudos buttons, 

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Good Luck.

[SherylA]

Thank you for the response.  However, it is not applicable.  Aside from wifi communications, the printer works perfectly.  As a stopgap, I have plugged in USB and that works correctly.  However, wifi is very hit and miss, with most of the time being a miss after the printer has gone to sleep.  You did not address the wifi issue.  Due to this, along with the plethora of complaints about spotty wifi connectivity here as well as all over the internet, I assume that newer HP printers simply are unreliable on wifi connections and this is a technical problem that HP needs to solve.  I have a large number of wifi connected devices, and none of them have problems with dropping connections and not recovering, like this printer does.  Therefore I assume the problem is with the printer.

[Riddle_Decipher]

@SherylA I understand and I suggest you try the below steps:

(Follow the below steps for performing a hard reset)

1. Turn the printer on, if it is not already on.

2. Wait until the printer is idle and silent before you continue.

3. With the printer turned on, disconnect the power cord from the rear of the printer.

4. Unplug the power cord from the wall outlet.

5. Wait at least 60 seconds.

6. Plug the power cord back into the wall outlet.

      NOTE:

   HP recommends connecting the printer power cord directly to the wall outlet.

7. Reconnect the power cord to the rear of the printer.

8. Turn on the printer, if it does not automatically turn on.

9. Wait until the printer is idle and silent before you proceed.

Try to print. If the issue persists, continue to the next step.

These steps are for setting up your wireless printer to stay connected to your router, keep wireless devices better connected and makes your router secure and hack proof.

1. Set a static IP in the printer (click here) outside the DHCP range of the router (check your manual). This is for Linksys routers but can be used for all routers. Verify your DHCP range and change this first if needed. More Wireless Printing help is here (Windows solution 4, static IP).
2. Verify in the printer that 'Auto Off/Sleep' is disabled.  Use the Embedded Web Server (EWS) by going to the printers IP address in your browsers address bar, click Settings Tab/Auto Off. Or use the Printer Assistant, Printer Home Page (EWS). Also check your Printers Properties.
3. If the printer supports and has IPv6 enabled, turn off IPv6 in the printer.
4. If needed and you assigned a static IP address, try using 8.8.8.8 for the Preferred DNS server and 8.8.4.4 at the Alternate DNS server. 
5. Verify the printer is on the latest firmware by checking with the HP Support site.

In the router: (Refer to your router manual for information) 

1. Use a fixed wireless channel like 1, 6 or 11, never 'auto', try channel 1 first then the rest. 
2. Set router to 20Mhz only, or 145Mbps depending on router. 
3. Always use WPA2-AES (Personal) encryption, but you can try ‘mixed’ mode. 
4. Disable WPS and never use it and disable UPnP for the routers security. Nobody can hack your system now and helps with wireless connectivity (if you want to know why, search the web).
5. If you have a dual band router (2.4Ghz and 5.0Ghz bands), make sure the SSID’s are NOT the same, they must be different for all bands, even for any Guest networks.
6. SSID broadcast must be enabled.
7. Save all settings. Power off both, wait 2 mins.  Power on router wait 2 mins. 
8. Power on printer and verify it reconnects to router. 

Windows 7/8/8.1 & 10 - Is Network Discovery on or off?

1. Control Panel/Network and Internet/Network and Sharing Center/Advanced sharing settings.
2. Under Home or Work (current profile) / Network Discovery.
3. Select "Turn on network discovery" and save changes.

Keep us posted,

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Have a great day!

[ErichW1]

Scanner worked fine. Now it doesn't. My experience is practically the same as the OP.

Having read the question and the proposed solution, I've arrived at my own.

I'm getting a USB cable.