Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
fine-tooth comb [ˈfaɪntuːθ-] n
to go through sth with a fine-tooth comb(fig) скрупулёзно изуча́ть (изучи́ть*perf) что-н
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.