Very recently I have connected my Samsung SyncMaster 940NW to Gadmei external tv tuner card and everything was ok except bad picture for low signal quality. Then I connected set top box to it and it improved the picture quality but at the same time horizontal bars of 1-2 mm thickness with 2-3 cm gap are coming in the whole monitor. I think that there is no problem in the monitor (no horizontal bar when set top box is not connected or used as computer monitor) and in the set top box (I have checked with different lcd panel).
So, friend, what's going wrong? Anyone with any idea and experience will be very much appreciated........Thanks in advanced.