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

[jenkem_lover]

I picked up an old medical monitor and a pretty cheap HP PC with Windows 7. The computer has an 8600GT with S-Video output which worked with the PVM before. Sadly, the HDD in the computer was on its way out so I had to replace it but now when I try to boot into Windows 7 I get a "No Sync" message from the PVM and obviously no display.

It displayed the OS on the old, dying, HDD so I plugged it back in, albeit with the SATA and power still connected to the new drive, and I had the same issue again. At first I suspected it was some kind of driver issue i.e., no NVIDIA drivers meaning no analogue signal from the card in OS, but now I can't figure out if the PVM is at fault, software, or the GPU. Perhaps Windows 7 by default outputs a resolution the PVM can't process?

I should also mention that the computer and PVM have no issue displaying the BIOS, it just displays "No Sync" when Windows loads.

If anyone has had a similar experience and knows what's going on, I'd really appreciate it!