Lenovo G505S parts
The motherboards inside Lenovo G505S - as well as small daughterboards - have been developed by Compal and manufactured by Palwonn and Hannstar PCB providers (according to the motherboard markings). Here are the schematics - (link here).
There are the following types of a primary motherboard available:
1) iGPU only ("HD 8650G" in A10-5750M case) - LA-A092P motherboard
2) iGPU + dGPU (discrete GPU) "HD 8570M" - LA-A091P motherboard (usually rev 1.0)
3) iGPU + dGPU "R5 M230" - LA-A091P motherboard (usually rev 1A)
Please note that to replace the LA-A092P motherboard with LA-A091P you would also need a heatsink with two radiators (one for CPU and one for dGPU) and they are hard to find separately, although you may try.
Also G505S has the following daugtherboards:
LS-9901P - one USB port + audio + card reader
LS-9902P - double buttons board which is possible to make by yourself
LS-9903P - double LEDs board
LS-9904P - SATA DVD connector board
To be continued...