It is not certain a "supply point" - BUT - I feel that if you went 6 stations down the Shumchun MTR line to Futian from Lowu, you be more sure of finding what you need in the huge, tall, emporia filled with computers and parts @ Seg Electronic Market Hua Qiang North Road, if not there, then in the many amazing multi-storey Malls cheek-by-jowl there. Just have plenty of RMB in the wallet, there's so much stuff you CAN'T locate in Hong Kong that IS there!
Get off at the TAIL end of the train and take the LEFT passageway out of the station, cross the road & SEG is riht there.
That area will "Blow your Mind" for parts [lower floors]
It's also a great money saver to get Laser cartridges refilled there too!!!