No display after changing boot mode to UEFI boot. What happened?

It happened to my Dell T1700. Enabled the secure boot in UEFI and boom, no video. Replaced the video card, had an ATI, replaces with ATI but different model. Same thing. The on board video does not due anything. Did all CMOS and PIA thing, no a chance. Is like an iPhone, if you forgot the Apple ID you have to put the phone in the bin. Anyone has a fix for this Dell “wonder” ?