For the (a common RTK2841-based Smart TV motherboard used in brands like Skyline, Prestigio, and Starwind), you can typically find firmware files on technician-focused forums. Firmware Downloads
If your TV is a SmartTech brand, they maintain a Downloads page for official firmware.
Technicians should verify the 12V and 5V standby rails. Download P75 2841V6 1920x1080 Revolution Galaxy part06 rar
Below is a proposed "paper" or technical report structure based on the hardware.
Surface-mount (SMD) chips and MOS transistors should be replaced using a hot air gun set to approximately 340°C. For the (a common RTK2841-based Smart TV motherboard
Paper Proposal: "Analysis of Universal Smart TV Mainboard Architectures"
Includes HDMI, USB 2.0, RJ45, and integrated Wi-Fi modules. Below is a proposed "paper" or technical report
This is a primary source for this specific chassis. You may find your exact version (Galaxy Revolution) under their P75-2841V6 sections . Note that registration or a subscription is often required to download.