ACER Aspire 5742 - Mic not working and constant high pitch sound

EAR90

Hi, i have been using my laptop for MS teams but was having an issue with what i thought was my sound to i made some changes but after taking my laptop apart - the sound was my fan as there was a lot of dust in it. Anyway, laptop back together and everything is working great, but when i was on a call to a colleague he could not hear when i was talking and could only hear the high pitched noise - i have tried to do all the check, change the frequency but nothing is changing...thanks in advance for any help!