I know it sounds silly but have you tried manoeuvring the monitor cable about a bit (i.e. jiggling it?). It could be something wrong with the cable, like there's a loose connection or a pin has broken. Failing that you could try and get hold of a scart converter cable (if your UkK of course) off e-bay and try that with your tv. Also if you've got the case open to try and reseat the chips try checking the cabling to the disk drive. The light not coming on in the top right is a bit worrying though, you should also hear a noise from the disk drive as the computer tries to boot a non existent disk.
RE: 1040STf won't go 
