When statically assigning phones, there are two methodologies... one is to manually set the necessary information in each field, the minimum required is
IP Address
Subnet Mask
Gateway
ICP IP Address (phone system IP)
TFTP IP Address (phone system IP)
This is generally all that is needed to get the phone to boot properly. Phones do not get updated to the latest firmware, the firmware must match what is in the PBX... if you upgrade a phone to something different, it will upgrade/downgrade itself when it properly connects.
The second methodology is to allow DHCP to give the device all the information EXCEPT the ICP/TFTP address (a normal DHCP offer) with no special information. Boot the phone and factory default it, then reboot the phone and press and hold 7 and setup Teleworker mode, select New, IPv4 (if prompted), then enter the phone system's IP address and press the VOL DN, Save and reboot.
If the phone doesn't pull firmware or boot properly, there are a number of possibilities to look at... is the phone in the same subnet as the PBX, if not it could be a routing, firewall, switch, or VLAN issue. These need to be addressed first... take a working phone and reboot it, watch the display, does it show anything different for VLAN or pause anywhere unique? Connect a phone that doesn't boot to the same port, does it act differently? Start the phone in configuration mode and go through the "Current Network Settings" paying attention to things like VLAN ID, ICP, TFTP, etc. and look for something that is either manually assigned or looks odd, these settings may have to be duplicated manually.
A trained technician could probably figure this out quickly, the problem is there are so many possible variables here it is difficult to pin it down in a forum sometimes.
As far as the blank display, is it just when in use (after booted) or does it work when you first plug it in? If it doesn't work when you first connect the phone, repeatedly press the VOL UP key to change the contrast and see if you can get a display. If not, default the set via configuration menu. If there is still no display, this is likely a hardware issue in the phone itself.