tv monitor stopped working

[phelplsy]

I use a hp computer with video card recomended by MTU. It
has one 1/4 video jack, s connection, and computer monitor
connection.

This has been working for first three shows, just didn't
after that. Computer monitor works fine. I turn the tv monitor
on first as instructed.

The tv monitor works until i load Hoster, then blinks and goes
blank.
My computer is well above requirements needed to run
Hoster.

Help.