a HD 6755G2 is either a Llano APU based A6(6520G) or A8(6620G) crossfired with a HD 6750M discrete gpu
Ah, so either APU should work with the Discrete GPU provided it's a 6750M. I've actually got the laptop running after a fashion with the A8 installed, but the only driver it will accept is a basic M'soft for the APU's 6620G, so confirms that the Discrete card is kaput. I'll wait and see what results I get when the Mobo is returned. Dealing with China can be cost effective, but comms are often very difficult!