I test all my equipment immediatedly after repaired, all on slide, plus developed, only within a day or two, if that is a problem, bring the slide and show to the technician, he should give full responsible, and fix your problem again, and this is also why I only used one of the local repair shop I trusted. I just send my black paint M4 for service two weeks ago ( shutter jam due to my careless), and they fixed it in 5 days, cost.... less than $200.00