Critical Update Required Troubleshooting

Critical Update Required

The Critical Update Required error message can appear when either bridgeOS is corrupt, or there is a hardware fault that affects bridgeOS.

Troubleshooting this error is difficult, follow the steps in order below to isolate the cause:

• Boot in to Safe Mode (by holding shift) and download MacOS 10.X combo update dmg.
• Create Time machine backup from safe mode (if possible/needed) and Reinstall a newer macOS if available.
• Make sure the Lifeboat connector cover is on the logic board. It is required to boot even to a known good external drive.
• Boot to a known good, Compatible macOS.
• DFU mode restore (T2 Macs only. Backup data if important)
• Boot the bare board with a known good USB C port, connect it to power, keyboard, USB C to video output, and known good macOS. Please note that not all USB C to video output adapters will display during the EFI portion of boot. The original Apple USB-C Digital AV Multiport Adapter did not. The second generation HDMI 2.0 adapter has not been tested.
  • If the bare board will not boot, you have a logic board problem.
    • Use a detailed visual inspection to look for bad test points, solder pads, and components. Repair any obvious damage.
    • Check power supplies of all components that can cause bridgeOS to fail (check list below).
    • Check all data lines of components that can cause bridgeOS to fail (check list below).
    • Check all data and power lines of NANDs. There are a couple of test points that tend to corrode and fail.
    • Flux and clean any BGA chips that might have been affected by liquid.
    • Check around Apple pay NFC Chip (U3905), PMU (U4200) area and check L4202-L4205 for outputs. That area is prone for corrosion, re-ball chip if necessary. (820-00239)
    • Ultrasonically clean the board. This is a last resort since it will likely erase signs of liquid damage. Take high resolution pictures before cleaning any board you work on. Bake the board at 125C for an hour with a PID Controlled Oven. Tiny amounts of residual liquid can disrupt some high speed communication lines under larger BGA chips.
  • If the bare board boots, you have a problem with a connected device. Connect them one by one until you get the Critical Update Required error again. The following components are known to cause this problem.
    • Touch Bar display
    • Touch Bar digitizer
    • T-Conn (this can be be cleaned with an Ultrasonic Cleaner.)
    • Touch ID (this can be be cleaned with an Ultrasonic Cleaner.)
    • Power button (this can be be cleaned with an Ultrasonic Cleaner.)
    • Anything controlled by T1/T2