That's a proprietary motherboard, so you won't be able to get a replacement upgrade.
You could upgrade the RAM, CPU (35W) and HDD
Which CPU do you have?
I would upgrade to a SSD and 8GB RAM (if you have 4GB)
These are CPUs upgrades supported on HP Pavilion 23-q003na with a Crusher-U motherboard
Intel Core i5-4460T (Haswell) 1.9 GHz Quad Core
Intel Core i5-4590T (Haswell) 2.0 GHz Quad Core
Intel Core i7-4785T (Haswell) 2.2 GHz Quad Core.