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CRT Monitor repair / STR

Sanjaya

Dec 13, 2011
10
Joined
Dec 13, 2011
Messages
10
This is a LG CRT Monitor. (White color, 15 inches, Not a Flat Screen). Its flyback transformer was replaced 3 years ago. Recently the picture was going into dark after about 2 hours of working. Finally it was completely dead. Now yellow light is flashing and when the computer is on, it becomes green and monitor automatically off. I heard some high pitch sound on the screen before it off. I opened it and checked and found that Main filter capacitor has a puffy head. I replaced it with a new one. But no any change happened. I replaced several electrolytic capacitors on primary and secondary power supply section. But no any changed happened. Is it can occur due to faulty STR? Is it needed to replace all the electrolytic capacitors? I checked all the diodes, transistors and resistors in the power supply section and horizontal deflection system. No any fault found. I like to know how to repair it. Please help me.
 

Sanjaya

Dec 13, 2011
10
Joined
Dec 13, 2011
Messages
10
STR

Can CRT Monitor give green light flashes and off if it's STR is bad?
 

moonmonkey

Dec 24, 2011
3
Joined
Dec 24, 2011
Messages
3
xray protect

the high pitch you heard was probably a problem with the hv supply ,maybe a horizontal output or another flyback, and now the xray protect shut it down ,,and now it went completly out, get a pinout of the flyback and remove it from the board to test it ,, but first look at your horizontal output and recheck all the components in the hv section. that big filter cap that was puffy, if the puffy part was a plastic peice on top it probably was ok,, moniters are tricky many have anolog,digital,and high voltage, high frequency electricity,,good luck
 
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