Dell P3421W not working with MacBook Pro Retina (mid 2012)?

The Mac uses a system that reminds me of “Plug and play” to determine what display is connected, and what its capabilities are.

To get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display. "No signal detected" is generated by the DISPLAY, not by the Mac.

This query is only sent at certain times:

• at startup

• at wake from sleep — so momentarily sleeping and waking your Mac may work

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• hold the Option key while you click on the (Detect Display) button that will appear in Displays preferences (from another display)

so try doing some of those things and see if the display comes alive.

Hi, h0bbit78…, hmmm, ‘‘tis a curious question

you have posted.. there are two firmware updates for your monitor, available HERE: https://www.dell.com/support/home/en-gh/product-support/product/dell-p3421w-monitor/drivers

and they are for Mac O/S… give ‘em a try, apply ‘em…

funny, Dell doesn’t usually support Mac, not officially as a general rule, if it works with Mac or with Mac OS X, great… if it doesn’t, it doesn’t… if you talk to Apple they’ll tell you they don’t offer support/help using Dell Products on a Mac ( with Dell and Mac OS X) … as they are not listed/ not known for being Mac compatible/Mac friendly… you could try asking on the Dell forums… your MacBook Pro Retina from 2012 will do MiniDisplayPort and with correct adapters, DVI, Dual link DVI , VGA or HDMI with miniDisplayPort to HDMI adapter… monitor has usb-c connection, DisplayPort 1.2 and HDMI 2.0, ensure your cable(s) or adapter supports any of that… otherwise, on the 2012 MacBook Pro retina, try a reset smc followed by 4 pram zaps on startup, per this link :https://www.macworld.com/article/224955/how-to-reset-a-macs-nvram-pram-and-smc.html… and power cycle the monitor, eg disconnect power cord/cable from monitor… wait about a minute or two.. and plug it back in-press power button on monitor… of course, all connection/ disconnection /changes between Mac + monitor must be done when both are powered down/turned off…

Right ! It’s 2nd breakfast time !!

john B

The MacBook Pro retina 2012 is a much older display technology. Displays technology has grown by leaps and bounds since it was issued.

2nd Display Support: Dual/Mirroring* 2nd Max. Resolution: 2560x1600 (x2*)

Details:* This model supports a simultaneous maximum resolution up to 2560x1600 on two external displays via Thunderbolt. Alternately, it can support a single display up to 2560x1600 via Thunderbolt and a single display up to 1920x1200 via HDMI.

from:

https://everymac.com/systems/apple/macbook_pro/specs/macbook-pro-core-i5-2.5-13-late-2012-retina-display-specs.html