Here someone from mhhauto.com provides a comprehensive list of which component on
Chinese SDconnect C4 mux to change to a genuine one, including the MLCC values
The RAM for the PPC on the top is DDR SDRAM (16Mx16) (search for k4h56xx38j_66tsop2_rev10.pdf). Alliance, ISSI, and Winbond make crosses for it. The parallel NOR on the CPU side is an S29GL (3.3V, 64Mbit, parallel NOR — you can still find those around without too much trouble).
The C166 you can find via Octopart (XC161CJ-16F40F). You will need to program the flash on this part if you just want to drop it in.
The switching regulators are mostly LTC3412A — you can find those without too much trouble.
You can find the Ethernet PHY AM79C874VI without too much trouble.
For the 4Mb/5V SRAMs on the back, you need a 5V TSOP-44 10ns 4Mb (or larger) SRAM. ISSI makes the IS61C5128AL, which I believe should be a drop in replacement.
The parallel NOR flash on the bottom could be more of a pain in the ass. You need to find a 16Mb (or greater) 5V 70ns (or faster, although this may not be super critical), AMD CFI compatible (if you want to be safe) flash in TSOP 48. These parts are long obsolete. You’re going to have to do some digging around to locate those.
The CPLD on the bottom is an LC4256V-75TN176C. You can still find those.
I can’t remember the part # for the Hynix NAND on the bottom, but I’ll update the post if/when I do.
So all this said…unless you are very experienced with rework and have good equipment, you could very likely end up destroying the PCB in the process of trying to do all of this rework. Reworking these boards is not something that’s economically viable as has been pointed out on here by Anturage before.
If you’re not equipped with rework knowledge and abilities, you’d better have a genuine SDconnect or a good clone of high quality at a decent price through a reliable source (tech support and refund is available if you have something wrong with the mux), such as http://www.obd2diy.fr/wholesale/bonne-qualit-mb-sd-connect-compact-4-star-diagnosis-201303-version-2500.html