Dump file conversion with iconv

I tried to convert the dump file with iconv. The command that I used: iconv -f utf-8 -t iso-8859-1 | iconv -f windows-1251 -t utf-8 Unfortunately, it converts to the unreadable letters: Îáúÿâëÿåòñÿ íàáîð ìîäåðàòîðîâ. It works correctly if it is only one phrase. From other thread I understood that the dump file might contain both text and binary data, and trying to interpret the binary data parts as text would most likely result in unreadable junk. I tried to convert SQL dump file from web forum with unknown coding to utf-8. It works correctly if it is only one phrase like in this thread: https://unix.stackexchange.com/questions/629040/formatting-from-iso-8859-1-to-windows-1251 . And it did not work for the file.