No dispaly on screen.

Three possibilities. 1) The LCD screen is cracked from a fall or hit etc.. It can be visible or a small crack hidden on and edge or corner, only visible after taking out the display. 2) The phone was exposed to moisture or high humidity long enough for corrosion to start. This could have happened many months ago. The corrosion has finally effected the LCD. If you're up to disassembling the phone you can clean the LCD connector with rubbing alcohol and a tooth brush as well as clean the LCD cable itself with a pencil eraser. Typically the LCD is held in with a little 2-color connector that you open with a tiny screwdriver or other tool by carefully prying off each side of the connector a little bit. (1-2mm) when you are done just slide the lcd connector in all the way and push the connector back in. 3) It's unlikely but the LCD can just stop working. It's not worth paying $30 to $50 for a new one. Just replace the phone.

I fixed mine by opening the handset case, and discovering that nothing was wrong or corroded, except that one of the charger contacts (the big and shiny long ones at the bottom of the handset) was a little loose. The two screws at the bottom of the circuit board also hold the contacts in place. Make sure they're tightened if they seem even a tiny bit loose.

The LCD was totally fine, and my contact ribbon for that was held in by tape and glue, so there was no way to check for internal corrosion KX-tga560m.