hello all,
sometimes there is a continuous noise come from WD HDDs mainly with L-shaped PCBs
with motor ICs ( Smooth 1.3) , (L6278 1.7) & (L6278 1.2).
the noise like : Trrrrrrrrrrrrrr or Trrrr....Trrrr...Trrrrr
so all we have to do for fixing this problem is:
1- clean the connection points which connect the head stack pins with the PCB using a pencil Rubber ...carefully... cause cleaning with force may remove one or more of the small capacitors or resistors on the PCB.
2- then clean the motor IC pins thoroughly using a solvent & Toothbrush.
-Note- the two steps mentioned above solve the problem in few cases.
3- if the two steps mentioned above didn't fix the problem , you have to replace the motor IC cause it's damaged.
-Note- in case of Motor ICs (L6278 1.7) & (L6278 1.2) first try to desolder them then resolder them again before u decide to replace them with a new ones ... this sometimes work , but if it didn't work ... replace them directly.
Best Regards & Good Luck
Ahmed_Samy