Carrier 42NQV050M Service Manual page 79

11-8-6. Checking Method for Each Part
No. Part name
1 Electrolytic capacitor
(For boost, smoothing)
2 Diode block
1. Turn OFF the power supply breaker.
2. Discharge all three capacitors completely.
3. Check that safety valve at the bottom of capacitor is not broken.
4. Check that vessel is not swollen or exploded.
5. Check that electrolytic liquid does not blow off.
6. Check that the normal charging characteristics are shown in continuity test by the
tester.
C12 C13 C14
C12, C13, C14 → 38NYV050M2,38NYV050M-A : 500µF/400V,
38NYV060M2,38NYV060M-A : 760µ F/400V
1. Turn OFF the power supply breaker.
2. Completely discharge the four electrolytic capacitors.
3. Remove the diode block from the P.C. board (which is soldered in place).
4. Use a multimeter with a pointer to test the continuity, and check that the diode
block has the proper rectification characteristics.
+
1
~ ~
+
3 2
1 2 3
–
4
– 78 –
Checking procedure
Case that product is good
Pointer swings once, and returns slowly.
When performing test once again under
another polarity, the pointer should return.
MCC-5009
Soldered
surface
Tester rod
+
~
2
~ ~
–
~
3
4
–
4
(DBO1)
10 to 20 Ω when the multimeter probe is
reversed
FILE NO. SVM-10052
Resistance value
in good product
–
+
1
∞
~
2
~
3