Get that Maxell battery outta there as quick as possible, it's a ticking timebomb.

Have you tried getting video out of the onboard video?  Then maybe we can get a Mac error code.

For the adapter, I'd try 13" mode 6 (sync on green), and then give mode 1 and 2 a try.

After that, I'd try one of the multiple-scans on modes 6, 1, and 2.  Use it with your ViewSonic CRT.