This a very "generic" ChiMei 19" 1440x900 monitor (brand is written very small in back label).
As soon as it is plugged to the wall, without input signal, it shows full screen color red, after 1-2 seconds, green, then blue, then white, then some gray levels. It doesn't respond to front buttons. With VGA signal, display is OK but shows a factory adjusting menu with an option constantly switching. Seems bad TactSwitch problem to me.
After opening I detect a bloated 1000uF/25V cap in power supply, but I'm sure that's not the problem. I replace it anyway, the problem stays. Remove the FFC cable that goes to front buttons PCB and the problem persists! I detect a lower resistance in the line of MENU button, in Main PCB. Follow to 10kΩ SMD resistor array RP47, remove it but still there. Then remove SMD capacitor array CP8 and now it goes away. One of the caps is shorted. After that, the monitor does the same, but only the 1st time: after power off it "forgets" about factory test mode.
Put back resistor array. It can live without the capacitor array.
As soon as it is plugged to the wall, without input signal, it shows full screen color red, after 1-2 seconds, green, then blue, then white, then some gray levels. It doesn't respond to front buttons. With VGA signal, display is OK but shows a factory adjusting menu with an option constantly switching. Seems bad TactSwitch problem to me.
After opening I detect a bloated 1000uF/25V cap in power supply, but I'm sure that's not the problem. I replace it anyway, the problem stays. Remove the FFC cable that goes to front buttons PCB and the problem persists! I detect a lower resistance in the line of MENU button, in Main PCB. Follow to 10kΩ SMD resistor array RP47, remove it but still there. Then remove SMD capacitor array CP8 and now it goes away. One of the caps is shorted. After that, the monitor does the same, but only the 1st time: after power off it "forgets" about factory test mode.
Put back resistor array. It can live without the capacitor array.