Q:

White screen when I fetch data from MySQL on PHP into an Array

I'm taking values from MySQL(PHPMyAdmin) to PHP and after that, I send them to an echo for taking those values on Ionic. I don't know why but when I add a specific value (Bio field from MySQL) inside the array and execute the .php file thows me a white screen.
Here is my code: 
json-tecnico.php
<?php

require_once('connect.php');

$consulta = "SELECT
                idTecnico,
                nombre,
                apellido,
                cedula,
                genero,
                telefono,
                usuario,
                correo,
                ubicacion,
                bio,
                rate,
                catg.descripcion Categoria_Descripcion,
                subcat.descripcion Subcategoria_Descripcion
            FROM
                tecnico AS tec

            INNER JOIN categoria AS catg
            ON
                tec.categoria = catg.idCategoria
            INNER JOIN subcategoria AS subcat
            ON
                subcat.idCategoria = catg.idCategoria AND subcat.idSubcategoria = tec.subcategoria
            WHERE categoria = '".$_GET['categoria']."'";

    if(isset($_GET['subcategoria'])){
        $consulta = $consulta . " AND subcategoria = '".$_GET['subcategoria']."';";
    }

    $resultado = mysqli_query($conexion, $consulta);

        while($columna = mysqli_fetch_assoc($resultado)){
            $data[] = array(
                'id' => $columna['idTecnico'],
                'nombre' => $columna['nombre'],
                'apellido' => $columna['apellido'],
                'cedula' => $columna['cedula'],
                'genero' => $columna['genero'],
                'usuario' => $columna['usuario'],
                'ubicacion' => $columna['ubicacion'],
                'bio' => $columna['bio'],
                'rate' => $columna['rate'],
                'subcategoria' => $columna['Subcategoria_Descripcion']
            );
        }

    if(!empty($data)){
        echo json_encode($data);
    }

    else{
        $data[] = array(
            'success' => 'No se encontro usuarios con el criterio de busqueda dado',
            'workers' => false
        );
        echo json_encode($data);
    }

      mysqli_close($conexion); ?>

The white screen shows when I put the '007' value on $_GET['subcategoria'] and when I put the line 'bio' => $columna['bio'].
On MySQL, bio is varchar(500). Why is this happening?
A photo of the "tecnico" table on PHPmyAdmin

A:

Well, I already dig into the problem, just was an Encoding error.
Using utf8_encode() on all the String variables solved my problem.

You can use this if you're getting encoding problems:
I got the Answer from here!

    function utf8ize($d) {
        if (is_array($d)) {
            foreach ($d as $k => $v) {
                $d[$k] = utf8ize($v);
            }
        } elseif (is_string ($d)) {
            return utf8_encode($d);
        }
        return $d;
    }

and after that:

    echo json_encode(utf8ize($data));

