"No Sync" on a Sony PVM-14N5MDE when booting into Windows 7

[Electronic M]

If the old HDD is still bootable and the data on it isn't corrupted I would use clonezilla to make a bootable copy of it and use the copy.
For old HDDs that may have unobtainable drivers on them it's a good idea to use a tool like clonezilla to make a backup image of the entire drive on a separate drive that you can reimage onto a new drive if the original dies.

If it's beyond any of that helping I'd try to make windows 7 update and get better drivers then I'd hook up a second VGA/DVI/Display Port/HDMI monitor (whatever newer higher rez output connector the graphics card supports) boot with only the newer monitor connected then right click on desktop select adjust screen resolution, detect additional monitors figure out which is the S-video output and try adjusting settings on it till it syncs and looks OK. It might have drifted into PAL mode when you're using an NTSC monitor or vice versa.