Monitor wasn't switching on, now swtiches on with two buttons. Dont switch off

[jonnybgood]

Hi,
I am trying to repait a Benq Q9T4 Monitor which wouldn't turn. I found some help online that they need to replace some caps on the power board. I check all the electrolytic caps with my DMM all gave good readings of capacitance and after the test they gave a resistance in the range of Mega Ohms so I thought they were good. I am i right?

I found a missing capacitor which looked to be missing from the factory while here, this guy had to replace it:

https://groups.google.com/forum/#!msg/aus.electronics/FZpdyCbSzng/nuy9nBk_SN4J

I put a 1000uF 16V as suggested.

Now, one has to push first the Menu button, then the Power, release the menu and release the Power again in order for the monitor to switch on. After that, I tested it with DVI cable and everything was oki. Can this be fixed. It it a sign of bad smd capacitor?

I think that the track of the power on switch should be going to a flipflop ic first and then to the microcontroller. Or else it could be that the microcontroller oscillator is only starting when I press two buttons. What do you think?

Here are some pics of the Driver board where the switches are plugged in. There are no loose
contacts.

The zeners seems to be oki (only tested for reverse voltage - they gave 0.7V)

Driver Board

connector of switch pcb to driver board

**broken link removed**

**broken link removed**

Switch PCB

**broken link removed**

 

[THINKER_KAM_MAN]

to be sure that the capacitors are good
you need to check the capacitors using an ESR meter or maybe a capacitance meter. or replace the capacitors.