If your 6270A pressure controller will not boot up (at all, or fully), a few things to check are below. Some also apply to the 2271A pressure controller.
1. Check that the Pressure Control Module (PCM) is fully seated
1A. Check that the two PCM hex bolts are tight. Slide open the front panel. Tighten the two hex bolts on the front of the PCM with a 6-mm nutdriver. Torque between 0.5 N·m to 0.7 N·m (4 lbf · in to 6 lbf · in).
1B. If the 6270A will still not boot up, remove the PCM and try again. If the 6270A boots, the display will show PCM where it would normally show which module is active (for example it would show "PCM instead of "Auto 30 psi", "Fast 10 psi", or Fixed 100 psi"). Once booted insert and tighten the PCM and see if it is recognized ("PCM" will go away). By this menu path check that the PCM serial number and control coefficients are shown: Setup --> Diagnostic --> Control --> Primary. See this article for more details on PCM communication problems, 6270A - Pressure Control Module (PCM) not communicating
1C. If it booted up, turn if off for 5 seconds then turn it back on and verify that it powers up and is working.
1D. If it still does not boot up, leave the PCM out and continue to 2.
2. Check that the front panel USB and power cables are fully seated
3. Format the internal drive and reload the firmware.
3A Plug the 6270A into a PC with a USB cable. The 6270A should appear as an external drive (just like a USB thumb drive).
3B. Right-click the drive letter for the 6270A in Windows File Explorer and select "Format...". Then do a "Quick Format" with default settings.
3C. Then copy the firmware update files from our normal 6270A firmware update page to the drive letter for the 6270A in Windows File Explorer and follow the normal firmware update process (wait 1 minute, turn off for 1 minute, then turn back on). Details and files here,
6270A firmware update instructions
If the 6270A still does not boot properly contact Fluke Calibration Pressure Technical Support at the below link or by calling 877.355.3225.