If your 6270A (or 8270A or 8370A) 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 although its PCM is not accessible without removing the enclosure.
1. Check that the front panel USB and power cables are fully seated
2. Check that the Pressure Control Module (PCM) is fully seated
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
6270A: Use a 6-mm nutdriver. Torque to 0.5 N·m to 0.7 N·m (4 lbf · in to 6 lbf · in)
8270A/8370A: Use a 6 mm hex head wrench. Torque to 10-14 N ꞏ m (7 - 10 lbf ꞏ ft)
3. If the controller will still not boot up, remove the PCM and try again
If the controller 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
3A. If it booted up, turn if off for 5 seconds then turn it back on and verify that it powers up and is working.
3B. If it still does not boot up, leave the PCM out and continue to 4
4. Format the internal drive
4A. Plug the controller into a PC with a USB cable. It should appear as an external drive (just like a USB thumb drive). If not, check that the setting at the menu path: Setup --> Instrument Setup --> Remote Port --> USB Setup --> "RS232 Emulation" is set to "Off".
4B. Right-click the drive letter for the controller in Windows File Explorer and select "Format...". Then do a "Quick Format" with default settings.
5. Reload the firmware
Update the firmware following the normal firmware update process
6270A firmware update instructions, by USB cable
2271A firmware update instructions, by USB cable
8270A/8370A firmware update instructions, by USB
6. Check that the front panel USB and power cables are fully seated
Check these at the front panel connections and at the other ends on the main board. To check at the main board, the top cover must be removed.
If the controller still does not boot properly contact Fluke Calibration Pressure Technical Support at the below link or by calling 877.355.3225.