The service manuel is very helpful, we where able to restore the device to its working operation again.
Text excerpt from page 9 (click to view)
KV-30XBR910/34XBR910
+B overcurrent (OCP) Occurs when excessive current �ows through R5013. The increase in voltage across R5013 causes the output of Q5004 to go high, and this high signal goes to the micro. +B overvoltage (OVP) IC6505 detects +B OVP condition and turns on Q6522. This sends a high signal to the micro and also shuts down the AC relay. V-STOP Occurs when an absence of the vertical de�ection pulse is detected by pin 24 of IC2801 (B Board). Power supply will shut down when waveform interval exceeds 2 seconds. White Balance Failure If the RGB levels* do not balance within 2 seconds after the power is turned on, this error will be detected by IC2801. TV will stay on, but there will be no picture. *(Refers to the RGB levels of the AKB detection Ref pulse that detects 1K). Low B OCP/OVP Occurs when set 5V is out. Horizontal De�ection Stopped Occurs when either: 1) a +B overcurrent is detected (IC5007), or 2) overheating is detected (Thermistor TH5002).
