I have two brand new monitors exactly the same model LU32J59 series. They do exactly the same thing. One is bad from the manufacturer. i know that cause i get these big blocks of colour and data on half the screen sometimes.. and it will go off and stay off.. toggle at the back is very flaky and not responsive or misreads the movement or ...now it hangs up and stops working altogether. I had a look inside ( I am an electronics technician) and I found that the driver circuitry for the backlighting is getting very very hot and then the component is shutting off and thats why you loose the image but the data is still active in on the display. You won't see anything without the backlighting... It just went off again.!!
This is a faulty design and manufacturing problem... not a one off issue. Samsung won't help me even though these monitors are just 1-1/2 months old. The 'good' one just goes off constantly and usually comes back on in a few seconds. This is a chronic design problem and a manufacturing/engineering error/defect/fault and Samsung should issue a recall !! They have not considered the component stress of 4K resolution at 60Hz in their design in this model. Trying to go cheap always backfires!!
They said because I have the monitors in Asia, they won't help me even though I bought them in NH USA... That sucks! Thats not customer service, that's customer neglect. Their own on-line customer service rep told me they won't help me!!??
Bye Bye samsung for me!!