Help please

On my iphone 3 when I listen to music my left earphone (skullcandy, also left earphone has mic) is much quieter than the right one. I've seen that to fix that you need to go into accessibility and equalise the mono sound. But when I touch accessibility the screen goes blank, the heading accessibility and the option to go back to General is still there but I need it to show accessibility settings. I've tried restoring my phone to factory settings and turned it on and off but nothing works, does anyone know how to fix either of the problems correctly or help me in the slightest? Thankyou