VARILITE VL4, Руководство пользователя

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C
HAPTER
3. M
AINTENANCE
P
ROCEDURES
3-95
02.9628.0010 CONFIDENTIAL
7-Oct-97
3.3.5.10 APS MJ10005 and IRF450 Transistor Removal and
Replacement ( Shop Only)
Parts:
1 EA TRANSISTOR, MJ10005 NPN 400V 20A TO3
(80.1612.1005)
1 EA TRANSISTOR, IRF450 NCH500V 10A TO3 (80.1610.0450)
1 EA INSULATOR, TO-3 (51.5005.0001)
Tools:
Screwdriver, Phillips #2
Notes:
1. IRF452 field-effect transistors (FETs) may have been used instead of
IRF450 FETs. When replacing IRF452 FET, either replacement FET may
be used, as available.
2. 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.
To remove and replace APS heatsink assembly MJ10005 transistor or
IRF450 FET:
Step 1. Remove power to luminaire.
Step 2. Remove power supply (Figure 3-27).
Step 3. Separate heatshrink from power supply chassis.
a. At power supply control PCB, remove four 6-32x3/4"PPZ
screws that secure heatsink assembly to power supply
chassis.
b. Gently pry apart sides of power supply chassis and remove
heatsink.
Step 4. Remove faulty transistor or FET.
a. At faulty transistor or FET (Figure 3-37), remove two
6-32x9/16"PPZ screws that secure transistor to heat sink
and remove transistor or FET and TO-3 insulator.