<?php
$html = file_get_contents('https://printerservis.net/canon_V3400.php');
$converted = mb_convert_encoding($html, 'UTF-8', 'Windows-1254');

// Decode HTML entities
$decoded = html_entity_decode($converted, ENT_QUOTES, 'UTF-8');

if (preg_match('/düğmesine/i', $decoded)) {
    echo "SUCCESS: Found düğmesine after HTML entity decode!\n";
} else {
    echo "FAILED even after decode!\n";
}

if (preg_match('/tuşuna/i', $decoded)) {
    echo "SUCCESS: Found tuşuna!\n";
}
