Video RAM Error Detected

It means you need to take your machine in to service if it doesn't fall under these programs:

http://www.apple.com/support/exchange_repair/powerbook.html

If the cost is too high, one of these companies may fix it cheaper:

http://www.dttservice.com/
http://www.powerbookresq.com/
http://www.microdocusa.com/
http://www.macspecialist.com/
http://www.techrestore.com/

Or if you can find the part and are technically minded, http://www.ifixit.com and http://www.xlr8yourmac.com/ have numerous logicboard replacement instructions.

The schematics of the logicboard are not available in the public domain as far as I know. So soldering it by hand would be a task only someone with the right schematics of the chip circuitry could do. That's beyond most anyone except the Apple design team's capability.