aoc monitor prob

greetings!!!

i am repairing a 14" AOC monitor, model: 5en, black chassis. Its first symptoms was a ticking sound with no other action. I found a shorted MOSFET transistor (IRF634B) in the secondary side of the low voltage PSU. Tested other components in the PSU but they are ok. After replacing the transistor, it now turns on but the display becomes too big and it comes on and off accompanied by a clicking sound. I observed that its the high voltage that comes on and off. Then after that cycle, there's no raster anymore. But the frontpanel light is on and the control for screen adjustments responds when pressed. Can anyone give me suggestions on how to fix the problem? thanks in advance.

regards,

ian b

Reply to
yhan
Loading thread data ...

an additional info to my previous post: after replacing the transistor. it stopped ticking. i measured the main B+ when not connected to video card. its only +90v. i think it should be 200. now, i noticed that when i connect the video cable to the video card, it attempts to display the information but resulted to whining on/off and blinking of power led (green color).Then i noticed the high voltage come & go. i measured the voltage during this phase. it rises and falls back to 90v. what am i missing?

thanks in advance,

ian

Reply to
yhan

i should say it happens whenever it receives signal from the video card.

Reply to
yhan

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.