C
HAPTER
3. M
AINTENANCE
P
ROCEDURES
3-107
02.9631.0010
CONFIDENTIAL
15 Jan 98
3.3.17.3 APS MJ10005 and IRF450 Transistor Removal and
Replacement
Parts:
1 EA
TRANSISTOR, MJ10005 NPN 400V 20A TO3
(80.1612.1005)
1 EA
TRANSISTOR, IRF450 NCH 500V 10A TO3 (80.1610.0450)
1 EA
INSULATOR, TO-3 (51.5005.0001)
Tools:
Screwdriver, Phillips #2
To remove and replace APS MJ10005 transistor or IRF450 FET’s:
Notes:
•
During VL3 to VL2B luminaire upgrade, IRF452 field-effect
transistors (FETs) may have been used instead of IRF450 FETs. When
replacing IRF452 FET, replace part with IRF450 FET.
•
Verify that replacement IRF450 FETs are manufactured by Motorola,
GE, or RCA. FETs manufactured by International Rectifiers (IR)
should not be used and returned to the shop.
Step 1.
Remove power to luminaire.
Step 2.
Open chassis lid.
a. At electronics chassis, remove six 10-32x3/8"PPB screws
that secure chassis lid to chassis and open lid.
Step 3.
Remove APS from chassis. Refer to Arc Power Supply
Removal and Replacement paragraph.
Step 4.
Separate heat sink from APS.
a. At heat sink assembly (Figure 3-37), remove four 6-
32x3/8"PPZ screws that secure heat sink assembly to power
supply assembly.
