i just had my aircon fixed and recharged with freon last saturday, after nun, i hear a brief squealing noise everytime magmamatic yung aircon fan, pag umiikot na ang fan, tahimik na, then maririnig ko nanaman pag nagmatic uli yung fan. binalik ko sa kanila, di rin nagawa, una sabi nila baka overcharge ang freon, binawasan pero ganun pa rin, then sabi nila makalawang na raw yung "plate something???"(naghohold sa belt) dun sa may compressor, baka daw pag pinalitan, mawawala na ang noise. he tried using the sand paper and giving it a wd40, ala pa rin. mga 2-5 secs lang naman ang noise but it irritates me everytime. what could be causing this? help po.