Successful tests have been carried out on a glass lift which has not worked since a Hampshire landmark opened more than a year ago.
The external glass lift has not been in operation since the tower opened
Portsmouth's Spinnaker Tower opened to visitors in October 2005, on the same day its external panoramic lift became stuck 30m (100ft) off the ground.
It has been closed to the tower's visitors ever since.
Builders Mowlem have now conducted 2,000 successful lift runs and the problems are "resolved".
David Greenhalgh, the £35.6m tower's project manager, said: "By the end of next week, we should know whether more tests need to be carried out or whether we can begin training with the operator, Heritage.
"We installed a relatively new piece of equipment, exposed to a strong south westerly wind, and with a lift which runs up and down a non-vertical face.
"The installation needed to be more robust, and we have spent the past year going through each element of the machinery and making it more so.
"We are now much more confident that we have resolved the problems and that we have a reliable lift."
Despite opening five years late, the 170m (557ft) tower saw 600,000 visitors in the first year, exceeding the 460,000 predicted by owners Portsmouth City Council.
Visitors have been able to access the viewing platforms via an internal lift.