# Unable to Print/Connect Via USB after Firmware Upgrade
**URL:** https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025
**Category:** Bug Reports
**Tags:** ender-3-v2
**Created:** [15 July 2022 03:40 UTC](https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025 "2022-07-15T03:40:09Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@3DPrintingNovist](https://marlin.crc.id.au/forum/u/3DPrintingNovist)
#### Post date: [15 July 2022 03:40 UTC](https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025/1 "2022-07-15T03:40:09Z")
Unable to connect to printer through printer software Pronterface. Cura Software Connected to Printer and Unit would Home and Level but would not print, Removed Auto-Level (G29) and System would Home Only and would not respond to printing commands through software. Ender 3 V2 Firmware dated 14JUL2022 on 4.2.2 Board.
Any information would be helpful. Thank you.
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### Author:  [@3DPrintingNovist](https://marlin.crc.id.au/forum/u/3DPrintingNovist)
#### Post date: [15 July 2022 03:45 UTC](https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025/2 "2022-07-15T03:45:15Z")
Note, Printer will not print using SD Card Either.
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### Author:  [@CRCinAU](https://marlin.crc.id.au/forum/u/CRCinAU)
#### Post date: [15 July 2022 04:07 UTC](https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025/3 "2022-07-15T04:07:03Z")
You don’t mention if you have a BLTouch installed or not, so I’ll assume you don’t…
Make sure the correct firmware you’re running is from:
> **[Ender 3 V2 - v4.2.2 Board - Stock - Marlin Firmware Service](https://marlin.crc.id.au/firmware/Ender%203%20V2%20-%20v4.2.2%20Board%20-%20Stock/)**
>
> Custom Marlin firmware for a Ender 3 V2 - v4.2.2 Board - Stock - 3D Printer, built daily to stay fresh.
You can’t use G29 without an BLTouch, so it would make sense that doesn’t work.
It’s also worth triple checking that you have a v4.2.2 mainboard via the silk screen printing on the mainboard.
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### Author:  [@3DPrintingNovist](https://marlin.crc.id.au/forum/u/3DPrintingNovist)
#### Post date: [15 July 2022 04:11 UTC](https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025/4 "2022-07-15T04:11:41Z")
My Apologies, Yes I have the BL Touch Installed and am using the following Firmware “Ender3-V2-BLTouch-20220715.bin” Along with the DWIN\_SET Files from the Repository for LCD Controller.
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### Author:  [@3DPrintingNovist](https://marlin.crc.id.au/forum/u/3DPrintingNovist)
#### Post date: [15 July 2022 04:12 UTC](https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025/5 "2022-07-15T04:12:22Z")
4.2.2 Version has been verified.
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### Author:  [@CRCinAU](https://marlin.crc.id.au/forum/u/CRCinAU)
#### Post date: [15 July 2022 04:49 UTC](https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025/6 "2022-07-15T04:49:05Z")
Just to rule something out - have you tried the MarlinUI builds?
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### Author:  [@3DPrintingNovist](https://marlin.crc.id.au/forum/u/3DPrintingNovist)
#### Post date: [17 July 2022 03:36 UTC](https://marlin.crc.id.au/forum/t/unable-to-print-connect-via-usb-after-firmware-upgrade/1025/7 "2022-07-17T03:36:56Z")
MarlinUI 15JUL2022 would not load to my system using any format or SD Card, The CrealityUI Version would load using file from 15JUL2022 but no USB Connectivity. I tried downloading multiple times.
I downloaded the 16JUL2022 MarlinUI Version today, with same SD Cards + Formatting, was able to successfully load the firmware and connect via USB.
Maybe just a bad file?
Regardless I am back online, Thank you for your time.