UPDATING
ENGINE DJ OS

To see which Engine DJ OS a unit is running, Denon DJ say to swipe down from the top of the screen to open the Control Panel and go to the ABOUT / UPDATE tab, which shows the installed version and whether an update is available. The files live on the Engine DJ downloads page at enginedj.com/downloads, under the OS section, per device.

Read the version first and write it down. If the update goes wrong, the version you came from is the first thing support will ask for, and it is the one thing you cannot read off a unit that will not boot.

Three ways to install, in Denon DJ's order. Wireless, which they recommend: enable Wi-Fi, open the Control Panel, go to ABOUT / UPDATE and select UPDATE if one is offered. The installer application: download the Windows or Mac updater, connect the unit by USB cable, power it on with the device-specific button combination, and follow the prompts. The USB drive: copy the .img file to the root of a drive formatted exFAT or FAT32, insert it, open Control Panel, ABOUT / UPDATE, find UPDATE FIRMWARE and tap REBOOT.

Wireless is recommended for a reason. It is the route with the fewest things to get wrong: no drive to format, no file to copy to the wrong folder, no button combination. Use it when the unit has a stable network. Use the USB route when it does not. The installer route is the one for a unit that is not offering an update on its own screen.

Their warnings, verbatim. Before starting: "Please ensure that all peripherals (Control One, Micro DMX, LC6000, etc.) are unplugged from the primary hardware before updating." During a USB update: "Do not power off." And for the installer route: "Make sure that any drives with a USB firmware update file are first removed when rebooting into FW update mode."

Peripherals first. A controller or a lighting interface on the unit's USB port is a device the updater may try to talk to, and a device it cannot finish talking to stalls the update.

"Do not power off" is the whole page in three words. The update rewrites the operating system the unit boots from. Cut the power in the middle and the unit may have half an old system and half a new one. Denon DJ publish no recovery statement for that case, and this site will not invent one: the way to handle it is not to be in it. Mains power, not a battery, not a venue's flickering socket, and nobody touching the unit until it comes back on its own.

Remove the update drive before rebooting into firmware update mode. A drive still carrying the .img file can start a second update from the first one's leftovers.

Never on the day of a gig. Never the night before one you cannot afford to lose. An update is a change to the thing you are about to depend on, and the whole point of the pre-gig checklist is that changes happen on a table, days out, with time to test the unit afterwards and time to go back if something is wrong.

Read the release notes before you update, not after. If a version has a known issue with your library or your drive, the notes are where it is written.

Say no. The prompt on the screen can wait until tomorrow and the set cannot. Dismiss it, play the gig on the version that got you here, and update on a table with mains power and no audience.

If someone already started an update in the booth, do not power it off. Let it finish, however long it takes. Everything else on this page is for tomorrow.