Easun IGrid SS 3KW Plus, Service Manual, Page: 26 / 29

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7.2.2.1 Major parameters of Booster section
The most likely problems occur on the Booster section including: broken IGBT, broken
Diode, and broken IGBT driver resistor. When checking Booster section, directly check
the MOSFET with Resistance probe or the Diode Voltage Droop probe with multimeter.
Checked components Instrument function
Referenc
e Value
Failed condition
Q13, Q14
(G, S) Resistance  25kΩ Short
(S, D) Diode Voltage Droop

0.5V Short or open
D15, D16,D17,D19 Diode Voltage Droop

0.4V Short or open
D18, D20(need to be removed from
PCB)
Diode Voltage Droop

0.6V Short or open
U7
Pin6,7-Pin5 Resistance

25kΩ Short or open
Pin2-Pin3 Diode Voltage Droop
 1.4V
Short or open
R129, R141 Resistance
 100Ω
Infinite or value
change
R130, R143 Resistance

2.2Ω
R136,R144 Resistance
 510Ω
Note: If IGBT or RESISTOR is damaged, it means that the Optocoupler may also be
damaged extremely. So replace it at the same time.
7.2.2.2 Major parameters of Inverter section
The most likely problems occur on the INV section including broken IGBT, broken Diode,
damaged IGBT driver resistor, damaged relative optical coupler.
Checked components Instrument function
Reference
Value
Failed Condition
QA1, QA2, QB1,
QB2, QC1, QC2,
QD1, QD2
(E, C) Diode Voltage Droop
 0.4V
Short or open
(G, E) Resistance

50 kΩ Short or open
D5, D6, D7, D8, D12, D13, D15, D16
(need be removed from PCB)
Diode Voltage Droop
 0.6V
Short or open
D3,D4 Diode Voltage Droop

0.6V Short or open
U1,U2,U3,U4
Pin6,7-Pin5 Resistance
 50kΩ
Short or open
Pin2-Pin3 Diode Voltage Droop

1.4V
Short or open
R48, R56, R78, R87, R49, R57, R77,
R86,
Resistance
 47Ω
Infinite or value
change
R42,R43,R54, R55, R60, R61, R83,
R82, R95, R94
Resistance

10Ω
Infinite or value
change
R105, R107 Resistance
 0Ω
Infinite or value
change
R193,R157 ,R208,R179 Resistance
 100Ω
Short or open
R182, R177,R209,R180 Resistance
 220Ω
Short or open