The trains were resumed after being suspended between Northgate and Shorncliffe stations in northern Brisbane on Thursday afternoon.
Just before 14:30, Queensland Rail told commuters that the problem had been resolved.
Earlier, a QR spokesman said that electricians were on-site to repair an "overhead electric line problem" affecting this segment of the Shorncliffe line.
Commanders were warned to wait for delays of up to 45 minutes when Queensland Rail announced the suspension at around 4:00 pm on Thursday.
"Customers can expect delays until our crews can fix the problem. We are online and available to help you with your questions," the spokesman said.