SIEMENS X300 SERVICE MANUAL
I recently had the same problems with two X300 myself and managed to find the problem.
The problem is either with the SW, DC-DC Power Supply, RC or TI-board.
1. Reinstall/reload SW. If message still appears, then
2. Measure testpoints for missing 12V. If missing, troubleshoot RC-board.
3. Measure testpoints for missing +-100V. If missing, take out TI-board and try again. If still
missing, it's most likely DC-DC Power Supply.
I've the test point values below. Hope this is useful
[Reference Number] [Title Test Point] [Value] [Tolerance]
TP1 P2.5D +2.5V ± 5%
TP2 P5D_PC +5.1V ± 5%
TP3 P5.0D +5.0V ± 5%
TP4 P3.3D +3.3V ± 5%
TP5 M12D -12.0V ± 5%
TP6 P12D +12.0V ± 5%
TP7 P12D_PC +12.0V ± 5%
TP8 PSRTRXVO 0 ~ 18.0V ± 5%
TP9 M100HV -100.0V ± 5%
TP10 P100HV +100.0V ± 5%
TP11 M14AQ -14.2V ± 5%
TP12 P14AQ +14.2V ± 5%
TP13 M2AG -2.0V ± 5%
TP14 P5AQ +5.0V ± 5%
TP15 P3.3AQ +3.3V ± 5%
TP16 GND NA
TP17 P3.3A +3.3V ± 5%
TP20 P5.0V-STBY +5.2V ± 0.5V