[SOLVED] Samsung U32D970Q works after slapping it (Hard)

[Timexxxx]

Hello I have a Samsung U32D970Q and it has an error I’m not able to track down any further.
The error pattern looks like this: The Background light is off and also the standby LED. But it is possible to see the monitor recognized in the laptop settings.

The weird thing is, when the monitor is in this state and I slap hard on the back of the monitor for several times it jumps on and also stays on. It is working correctly then (during a workday) and switches into the error state a while after my workday or after two.

I also have opened the monitor and measured the voltages around the power supply. When the monitor is in the error state, the voltages to the mainboard are around a 1 V level. When it’s working correct, they are about 12,9 V. I can see a DC voltage about 210 V behind the DC/DC

All Fuses and diodes are ok, I’m not sure which part gets triggered by the slapping.

Test1: When I bridge the PS_On/Off Pin to GND, the voltages for the 13 V Pins are around 10,3 V. So I guess there might be some bad caps. I don't have a multimeter for cap testing, do you have a guess how to check this systematically?

Test2: After removing the bridge PS_On/Off - GND The voltage for the 13 V Pins git to 12,9 V. Maybe PS_On/Off to GND wasn't the supposed switch on signal. But the question is why did the voltage is now 12,9 V instead the 1 V in the error state with everythin off

 

[geofelt]

You see the monitor in the laptop because the laptop graphics adapter can sense a connection.
There is likely a loose connection somewhere that needs to be fixed.
Mechanically jolting the unit temporarily fixes it.
It is a nice monitor, but considering the age, your only likely option is to replace it.