Sam4s ER-350 II SERIES - Troubleshooting; Power Problems

SAM4S ER-350II SERIES 6-1
6 Troubleshooting
This chapter describes the methods for determining the source of malfunctions in this ECR.
6-1 Power Problems
1. Check the power cable.
2. Check the power switch PCB.
3. Check the power transformer.
4. Check the power +30V.
• Check the Bridge Diode W02G (BD2) Output. (Pin number 1)
• Check the Transistor MMBT2222A (Q8) collector. (Pin number 2)
• Check +30V whether it is short.
5. Check the power VDISP.
• Check the VOLT_ONOFF signal ‘High’. (U5 74HC14 pin number 8)
• Check the Transistor MMBT2222A (Q3) KSA708-Y(Q5).
• Check VDISP whether it is short.
6. Check the power +28V.
• Check the Bridge Diode KBU6B (BD1) Output. (Pin number 1)
• Check +28V whether it is short.
7. Check the power +24V.
• Check the Transistor TIP142 (Q6) Collector. (Pin number 3)
• Check +24V whether it is short.
8. Check the power +5V.
• Check the Regulator IC MC34063 (U2) .
• Check the Transistor KSA1010Y. (Q9)
• Check +5V whether it is short.
9. Check the power VLCD.
• Check the VOLT_ONOFF signal ‘High’. (U5 74HC14 pin number 8)
• Check the Transistor MMBT2222A (Q11) KSA708-Y(Q7 , Q10).
• Check VLCD whether it is short.