My Panny SA-HE200 was refusing to start and showing F70 error. Googling the error showed a blown fuse. I replaced the 1.25A fast-blow fuse and it lasted about 2weeks, then I replaced it again, and again, and again . I was replacing the damn fuse every 7-10 days for about a year and believe me it was a PAIN. Then someone suggested I try a slow-blow fuse as he reckoned that a surge when the amp starts up was pinging the fast-blow fuses. It worked A TREAT, I've had the same slow-blow in for 10 weeks now and no problem. Hope this can help others!