Using ICs AL1500 and VIPer22A
No DC voltage present across C6
– Check the AC fuse F1. Check the
rectifier diodes for open or shorted junction.
Check them out from circuit.
Check C3 (0.1UF for short circuited junction).
Check the resistance of
terminals 5,6,7,8 and pins to 1, 2 of IC1 VIPer22A for short circuit. If show very low DC resistance, the IC is
shorted and the fuse will blow up.
Before replacing this IC, check all the other components connected with
it. Especially check C7, R3, D6. If any of these components are damaged or
there is any loose solder terminals to these parts, the IC will get
shorted.
If the photo-coupler IC2 is
found open or damaged, replace IC3 along with it.
If AC fuse is found open, check
the capacitor C8 connected to DC supply ground and the floating ground for
short circuit. It is venerable to damage
during lightning.
SCHEMATIC
SMPS SCHEMATIC USING AL1500 AS CONTROL IC
CLICK ON THE PICTURES TO ZOOM IN
