imageCLASS MF751Cdw II, unable to scan, communication error

[bb763]

Purchase this printer Dec 2025 to replace an HP that started having smudges that weren't from toner cartridge.

It's been a pain since the beginning.   The main issue is I'm away for most of the day or come in in the morning and the printer won't print, won't scan.   I have to turn it off then back on, then it starts working while I'm using it, until it sits for too long.  

Connected to wifi (same as HP and the computer).   I setup a manual IP because on HP that was always best but changing it for this issue on the canon didn't make a difference.

So I figure maybe a firmware issue, I push the upgrade firmware option, and it just spins until it says, "communication error".    Can't check for firmware update.   After this, I'm going to double check the wifi router to ensure there isn't a block outside the DHCP range since that range is .100-.200 and the printer is .20.

Any ideas on what is going on with this printer?

TIA!!

[shadowsports]

Greetings,

I've heard this report from others.  The two things that I would recommend are: 1. setting a static IP and 2. updating its firmware.  Based on feedback from others, this resolved the falling to wake issue.  It didn't appear to be related to setting the static IP, but this is best practice for a persistent device anyway and something I always recommend.  

I use a similar IP scheme on my network.  CIDR /24.   DHCP pool 192.168.1.100~192.168.1.200, leaving .2~.99 and .201~.254  for static IP's.  Been this way for 15 yrs and I have never had to touch it.  

I suggest you get your firmware issue resolved so you can update.  I noted v02.02 was released February 6th 2026.  Although it doesn't call out a fix for waking up, I would suggest upgrading.  If the printer has internet connectivity, the problem is often related to DNS.  

Try changing the primary DNS settings on your router to cloudflare or Google.  1.1.1.1 or 8.8.8.8 temporarily.  You have to reboot the router and the printer before trying the firmware update from the LCD again.  

If that continues to fail, then you can grab the firmware from the product's support portal and use a USB cable. 

Canon Support for imageCLASS MF751Cdw II | Canon U.S.A., Inc. https://share.google/ZopihbiVH3uxpFa43

Make sure you don't send any print jobs to the printer or operate the touchscreen when performing the firmware upgrade.  Let me know if this helps. Like I said, other users have reported a positive result.