have some old toy optiplex dell prebuilts with 3750s I play with, one will not boot to display… fans spin just no display or keyboard. However, but the jumper to service model , get display and keyboard, got to bios, got to diagnostic Password Jumper/ service mode is the only failure detected in diagnositc run which I have it jumped that way to run the maintenance mode.
Any Ideas? Again no display, mouse , but fans all spin and putting in jumpered service mode I get everything running and diagnostics passed.