1995 Chevy Blazer Car doesn't turn over

Hi,

I have a 1995 Chevy Blazer with a 4.3 liter V6.
When I went to start my car, after sitting for several hours, it started/died twice and now the engine does not turn over. I can hear and feel the starter trying real hard to crank it (lights dim), but the engine doesn't budge. I removed the serpintine belt - but it still doesn't crank. At first I thought the engine was siezed, but it cranked over briefly today. However, now it's wedged again.

My question is: is there any chance this could be caused by a failing starter? I read something about a stuck pioion in the service manual, but not sure if this is a standard transmission thing.

thanks in advance

paul