Yes it's closed until from 6-26 March 2019.

"NGONG PING 360 CABLE CAR TEMPORARY CLOSURE 6th to 26th March 2019 - The Ngong Ping 360 cable car operating between Tung Chung and Ngong Ping is to close for scheduled maintenance from 6th to 26th March 2019 (21 days). Normal service will resume on 27th March. During the closure period Ngong Ping Village, the "Big Buddha", Po Lin Monastery, Wisdom Path and other attractions at Ngong Ping remain open as usual. Visitors can take alternative transport between Tung Chung and Ngong Ping, either New Lantao Bus Company service 23, which takes about 50 minutes and departs from Tung Chung Temporary Bus Terminus, adjacent to the cable car terminal on Tat Tung Road (additional services operate to meet demand) or, subject to availability, Lantau (blue) taxi, fare approx HK$180, journey time about 35 mins."

Hope this helps.

I went around 9:15 am and the ticket office opened at 10 and there were long queues even on a weekday. You do not need to use a tour company as there is a MTR station just across the road.

It was not close when we were there. Go early in the am should be better. Strange they shoukd have tickets cos i saw many in q go online to buy tickets then they just switch to the direct to cable car q. There will be people asking you pay them so they gring u to the voucher line...