PMB_SR Microcontroller Internal Fault

What does STA1 (PMB_SR) Flashing mean?

The STA1 (PMB_SR) μC USB LED is flashing at a rate other than 1 Hz (normal) or 10 Hz (boot phase), indicating an internal fault within the PMB_SR microcontroller. This suggests the microcontroller is not operating correctly, possibly due to a core component malfunction or a corrupt firmware state. The fault might be related to the power supply to the module or internal processing errors.

1. 1

   Check the infeed power supply at connector X1.

2. 2

   Verify the status of the PWR/5V LED. If the PWR/5V LED lights up, exchange the CCU_SR module, as the internal fault persists despite power being present.

3. 3

   If the PWR/5V LED is not lit, troubleshoot the 5V power supply before considering CCU_SR module replacement.