<?php
// Let's test treating the mojibake as UTF-8, converting back to TIS-620 to get raw bytes,
// and then treating those raw bytes as UTF-8.
$corrupted = "เธชเธกเธŠเธฒเธข เธชเธฒเธขเธŠเน‰เธญเธ›"; 
$raw_bytes = mb_convert_encoding($corrupted, 'TIS-620', 'UTF-8');
echo "TIS-620 -> UTF-8 Bytes: " . $raw_bytes . "\n";

$raw_bytes2 = mb_convert_encoding($corrupted, 'Windows-1252', 'UTF-8');
echo "Win-1252 -> UTF-8 Bytes: " . $raw_bytes2 . "\n";