ViewSonic VX2435WM blinking black screen, HDMI Cable attempt

Hi, this time i&back on my actual computer (with Ati 5870 and Nvidia 9500gt graphic cards). This time i will try a brand new native HDMI cable (bought today, not used or old one), to see if the problem could be the cable. So far i could test that it is not a computer problem (tried two VERY different computers), not a VGA problem since I tried Ati 5870, Nvidia 9500gt (both DVI and VGA connetion), Ati X850. So last attempt is the cable... was the DVI-to-HDMI cable faulty? RESULT: NO! new (and different kind) of cable, same blinking. So the tests and results are: 1)On Nvidia 9500GT with DVI-to-HDMI cable (in HDMI INPUT MODE): black screens 2)On Ati 5870, 1st DVI output with DVI-to-HDMI cable (in HDMI INPUT MODE): black screens 3)On Ati 5870, 2nd DVI output with DVI-to-HDMI cable (in HDMI INPUT MODE): black screens 4)On Nvidia 9500GT with VGA cable (in D-SUB INPUT MODE): everything&fine 5)Using a Playstation 2 with S-VIDEO connection: everything&fine 6)Tried my father&pc which has ATI X850 gpu with DVI-to-HDMI cable (in HDMI INPUT MODE): black screens 7)Tried a different cable, this time NATIVE HDMI (not DVI-to-HDMI cable): (in HDMI INPUT MODE): black screens so the final RESULT OF MY TESTS IS: if i use the HDMI input of my monitor, no matter the source, after a while it blinks and gived black screens. Trying connecting a different source like Playstation 2 in analog connection way like S-Video, gives no problems. Trying one of the sources which gave the issue like the...