You can typically find these files on dedicated LED TV repair forums or technical communities:

: Sites like LED TV Softwares and community forums like Lab-One often host these multi-part RAR files. Installation Method : Download all parts (including Part 04).

Insert the USB into the TV and follow the specific boot sequence (often holding the power button while plugging it in) to start the update. About the CV358H-B42 Motherboard

smart TV motherboard, specifically for a panel.

It sounds like you're looking for the fourth part of a multi-part for the CV358H-B42

Because firmware files for these boards are often split into several parts due to their size, you need all parts (Part 01 through Part 04) downloaded to the same folder before you can successfully extract the final .bin file. Finding and Using the Firmware