Error code

From my experience can assume that error codes for ep, ec, st, et are the same, taking into account some features. Error code for ST E24: Low Voltage Power Supply Voltage Out of Tolerance . The computer has detected one or more of the low voltage power supplies is out of range (±12Vdc or +5Vdc). Measure power supply voltages (+12V at TP9, -12V at TP5, and +5V at TP3) on Main Board. Check operation of Q13 and U20E.