Hi I would like to appreciate for your help I have got an Acer monitor model G781 CRT Type its switching power supply is not starting 300 volt supply is ok , Q602 (2SK1940 )& ic 601 (UC3842)have been changed with new one, switch transformer is ok .but it does not start . still I have no schematic diagram to trace & trouble shoot . any kind of help will be usefull .
I have a samsung make 29" monitor and at start up its normal but after few minints the picture is starts flickering and increase gradually and after almost 15min all screen goes spraded that even cant c the pic, please help for the same
Posted on Sep 15, 2008
MONITER DELL 17 D1028LR R3550
Posted on Jul 10, 2008
I bought lg 17"monitor on last year but now i am having problem my monitor does not getting the power to strart
Posted on Apr 11, 2008
Replace the main board to solve problem
Posted on Jan 31, 2008
The mains switch is a weak link on these, check this first. Also 1 of 2 33K 2W startup resistors in PSU goes o/c, check with DVM or if you have very high volts on main primary res cap this usually indicates a 33K has gone - change both. I've also had a small TO92 transistor hanging off the UC3842 failing causing no startup. A s/c HOT normally causes a blinking LED. note that AC cap IS charged, DISCHARGE BEFORE WORKING ON IT! Did you check for shorts in the secondary side of the p/s, horiz output? If there are none , look for the switching regulator. Check the support components. I've seen these with open solder connections on the coils in the PS due to that abominable glue they use...you'll see signs of burning/arcing on the inside of the cabinet, too. Good luck
Posted on Apr 11, 2006
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Checked output circuitry for short , there was no short .
As the primary & secondary circuit were checked for active components & suspecxted passive components,this time cheked the passive components very precisely & find out the R627 a 10K ohm resistor , in one end is 10k & the other end is infinity !
So replaced R627 , & the system is started .
circuit
HANNS G HU196D DRIVER <<<<
power supply failure str burned i cant identyfiy str number
power supply
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