Can I use an iMac 2017 as a display for MacBook Pro 2019?
Can I use an iMac 2017 as a display for MacBook Pro 2019?
Question marked as
Please refer to Use your iMac as a display with target display mode - Apple Support, the answer is likely no. Please remember iMacs are computers, they were NEVER intended to be external displays for other devices. If you MBP needs an external display, please buy one, they are cheaper than expensive cabling solutions, more reliable than TDM and are MUCH more simple to set up than TDM. If you are in the USA you can find external display starting below $100.