I've had the bad idea to upgrade the firmware of our Epson WF-7840 (version CD17M6 now).

Now, our non epson cartridges are not recognised anymore.

I've search the web about how to downgrade the firmware. I found the procedure, found how to put the printer in "recovery mode" and, on the Epson website, I found the "Recovery Mode Firmware version CB08LC" for the Epson WF-7840.

But it doesn't work...

First problem, the model of the printer does not appear in the "Epson firmware updater" but it sees that a printer is connected.

Second problem, and it is where it stops, when I launch the Update, it fails with a message on the printer's screen "Data file not found".

I tried with my mac (macbook pro 16" m1 max) and with an older macbook pro from 2009 with the same result. I tried with another USB cable and still no luck.

What am I doing wrong?

⟐ Commented July 31, 2026 at 5:52 MST

I'll unplug it and do the power drain with the button and it comes back on, and will continue to do this about every 5-8 minutes, but always comes back. Any idea what the problem could be at this point? Would it be the main logic board, like a capacitor that could be bad? I can tell it's still getting power and doing something because the computer is still seeing the monitor in the display properties, and it'll come and go as you plug and remove the hdmi cable.

I've tried the easy things, different cables, different computers, updated drivers, all with the same results. And it is plugged in to a surge strip, if that makes any difference.

Thanks for any ideas!

⟐ Answered July 31, 2026 at 1:02 MST

⟐ Commented July 31, 2026 at 0:46 MST

I'm hoping someone can point me in the right direction.

My Brother printer has started printing very faded black text, but color prints still look completely normal. Photos and colored graphics come out fine, yet black documents look light and patchy. Sometimes there are faint horizontal lines across the page as well.

Here's what I've already tried:

• Ran the built-in cleaning cycle several times.
• Checked that the black cartridge isn't empty.
• Removed and reinstalled the cartridge.
• Printed from both Windows 11 and my Android phone.
• Updated the printer driver.

The strange thing is that the problem is exactly the same regardless of which device I print from, so I'm wondering if it's a printhead issue or something else inside the printer.

Before taking it apart, is there anything else I should test or inspect? Has anyone had a similar issue with a Brother printer where only black output is affected?

Any advice would be greatly appreciated. Thanks!

⟐ Answer edited July 30, 2026 at 17:04 MST

Thanks.

Unscrew all screws including ones under the rubber.

⟐ Commented July 30, 2026 at 0:30 MST

I've tried different power cords, different HDMI cables, but to no avail.

Do I just have a faulty monitor? Can I fix it at home or go somewhere to get it fixed?

⟐ Commented July 29, 2026 at 20:28 MST

Just for background my device was connected to the outlet when the electriction "tested" turning on power.

⟐ Commented July 28, 2026 at 20:20 MST

⟐ Commented July 28, 2026 at 17:59 MST

⟐ Commented July 28, 2026 at 10:00 MST

Is the optical sensor easy to replace? Could this perhaps just come loose?

Any experience with this issue would be greatly appreciated as I haven’t seen anything pertaining to this particular mouse.

TIA

⟐ Commented July 28, 2026 at 8:50 MST

I am beyond frustrated and I refuse to reset it up each and every time I have to print. I called Brother and their response was that the printer needs to be within three to five feet of the router (???!?!?). They said that the printers are "very sensitive" yet it's a "wifi issue, not a printer issue".

I never would have spent $150 for a wifi printer that needs to be literally next to my modem to work. I may as well have it wired directly. I have a small condo (1000 square feet) and the printer is in the room next to where my modem is located. It's maybe twenty or thirty feet away. There is no solid wall separating the two rooms--there's a large double doorway between them.

I'm so frustrated and upset that something so new and not inexpensive is useless. Do I have any options to keep the machine from constantly dropping the connection? I read somewhere else about "fixing" the IP address but before I mess with that want to make sure that is the right thing to do. Thanks!

⟐ Commented July 28, 2026 at 7:23 MST

⟐ Answered July 28, 2026 at 5:18 MST

⟐ Answer edited July 27, 2026 at 11:35 MST

How to fix it?

⟐ Answered July 27, 2026 at 7:04 MST

⟐ Commented July 26, 2026 at 22:41 MST

⟐ Commented July 26, 2026 at 16:16 MST

⟐ Answered July 25, 2026 at 4:12 MST