Goodmans GHDD177DVDR Initialisation?

After date time loss successfully replaced Lithium battery on Goodmans GHDD177DVDR 3 years ago. After same problem the unit has not reinitialised, I have cleaned all the obvious growth build up on accessible pcb tracks but now need to replace the miniature 3 pin component near the mark R378.
Please can you identify a suitable replacement?
The green light still appears, the hdd powers up but there has been no further apparent function since the required battery replacement.