Eurostar, Thalys and services to the north of France were interrupted about midday on Friday because of the electrical fault at Pierrefitte, north of the capital.
It was repaired about an hour later (11.00 GMT) but there were delays of between 40 minutes and two hour 30 minutes during the afternoon.
Traffic was not expected to return to normal until the evening, officials of the SNCF rail company said.
The rolling rail strike continued on Friday and Saturday, as many families left for their summer holidays, but with fewer workers joining the stoppage than on previous days.
Just 6.5 percent of SNCF staff stopped work on Friday, according to management, although 22.4 percent of train drivers did not show up for work.
Four out of five TGV high-speed trains were running as were two out of three intercity services.
Two of the most militant unions said they would continue their campaign ahead of negotiations on conditions arising from the government's rail reform.
They have set a new date for a strike on 19 July.