Tweco 151 with SL100SV - Manual (Page 90)

SERVICE 5-22 Manual 0-4691
5
E. Gas flows; AC indicator and GAS indicators ON; TEMP indicator off; ON; DC indicator
off or blinks on/off once.
1. Faulty IGBT or Output Diode Module Assembly(s)
a. Check per Subsection 5.08-C; repair as needed.
2. Faulty Main PCB
a. Test; repair as needed.
F. Gas flows; No arc in torch; AC , GAS , and DC indicators ON; TEMP indicator off
1. Faulty IGBT(s)
a. Measure between the following points on the IGBTs:
• IGBT A: E4 to E10
E10 to E20
• IGBT B: E23 to E27
E27 to E30
Voltage should be approximately 20 vdc before the start signal is active. If voltage measures greater than 100
vdc when the start signal is active, replace the respective IGBT(s).
E2
E3
E1
Secondary
Transformer
#32
#27
Input Diode
(mounts to
center chassis)
E1
E3
E2
Fuse
LT1
E33
J25
E10
E20
E7
E15
E30
E27
E32
J26
E23
J23
J24
J34
J33 J32
J18 J29
J27
J43
E5
E6
E4 E12 E17 J30 J31
E22
Art # A-04640
IGBT
PCB
E12 E17
TP4
TP1
J15
J11
J17
J16
U1
IGBT
PCB
IGBT
Module
IGBT
Module
Logic Board
Not Shown
Main PC Board Layout