Sam4s ER-420F - Key Board Problem

SAM4S ER-420M/F SERIES 8-1
8 Troubleshooting
8-1. Power Problem
End
Power
Problem
Power Out
Ok? On Trans
Y
N
1. Check the Power Cable
2. Check the Power S/W PCB.
3. Check the Power Transformer.
Power VDISP
(+30V) Ok?
Power VDRV
(+30V) Ok?
Y
1. Check the Fuse (FU1) on Main PBA
2. Check the Bridge Diode(BD1) on Main PBA
3. Check the VDRV signal whether it is short.
1. Check the Bridge Diode(D2,3,4,6) on Main PBA
2. Check the VDISP signal whether it is short.
N
N
Power +24V
Ok?
Power VCC
(+5V) Ok?
Y
Y
1. Check the IC LM2574HV (U2)
2. Check the TR1010,708 (Q4,Q6)
3. Check Generated Frequency
4. Check the +24V whether it is short or open.
1. Check the KA34063(U5)
2. Check the TR KSA1010(Q5)
3. Check the VCC whether it is short or open.
N
Y
N