Black screen,still has sound and lights

So I recently found my old Nintendo 3ds xl from a few years ago. I tried turning it on but there was no picture all I heard was the start up sound and saw that the power and Wi-Fi buttons were working normally. I contacted Nintendo support and they told me to reset it by holding the power button it did not work tho. Then I tried the A+up+L+R Method it the screen did turn on but after I did the whole Wi-Fi thing after it shut down and turning it back on it was again all black with sound. If anyone can help me I would greatly appreciate it .