Power and adapter dead and no output from power supply .
First of all check 300v at MFC (main Filter Capacitor)
collector of switching transistor or Drain of SW. Mosfet 300v supply pin of
STR.
If it is nil => then check AC input 220v AC but it is nil then check power cable and AC
socket for loose contact.
If input is ok but 300v nil at MFC then check any component
open in series direction line to the (+/-) terminal of MFC.
If problem shootout by impedance for impedance testing at line
track (multi-meter adjust RX1 range )black probe attached with line input track
red probe 7attached with positive terminal of MFC if near about .12 ohm to 25
ohm means ok.
If high or nil resistance show then check series component may be open type
faulty for neutral track checkingattached with neutral .
Black probe attached with negative point of MFC near about 12 ohm to 25 ohm indicate is ok .but nil
showit means NTC OR bridge diode is
faulty.
If 300v is ok then check near about .5v to .8v base or gate switching
mosfet.
If it is nil then check kicking fast pulse
resistance/trigger resistance is faulty attached between 300v track to
baseof switching transistor and check
near bout 20v to 30v at trigger pin of STR(if STR use in power supply).Mostly attached between 300v track to trigger
pin of STR by help some high value resistors.
Or AC input to STR by the help of Diode and Some High value
Resistor .
If trigging voltage not available then check its related
component. If OSC IC use in osc circuit then use some method of CRT power
supply .
if 300v availabel at collector of switching mosfet and supply pin of STR and trigging voltage is ok but no output from the secondary then check regulator Transistor used in primary side and check opto coupler and SCR attached between primary and secondary of some component.
If it is ok means STR is defective so replace STR. but after check any shorting component in secondary side.
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