All laptop motherboards are produced by 4 main manufactures.
All main brands are using them in their laptops- that's why the part numbers are different for each laptop.
Before buying you need to have it part number which is present only on the motherboard itself.
For doing that you need to dismantle the laptop to have access to the motherboard.If you don't have enough knowledge - don't try to do it by yourself you can damage other parts of laptop.
After you've the extracted motherboard please look at all inscriptions through motherboard : usually for ACER it is present in this manner 48.4Q901.021 ,for ADVENT is 15-F64-012001 (for FUJITSU may be the same),COMPAQ/HP part number looks like that 449901-001.So lets go to the DELL - their part numbers are 0M826G,
0C235M , if talking about SONY you'll find the part number looks like that: 1P-0071100-6010.And at the end we can speak about TOSHIBA Part Numbers - which are 1310A2175004 or HTW20 LA-3171P.
After you've your part number - you ready to buy the motherboard.
PLEASE NOTE: The best way to replace you laptop motherboard - to have it Part Number otherwise your laptop CPU & RAM may not feet your motherboard & the laptop will simply not work.