Halim, I've been fixing up an older Obie myself and your problem sounds much like mine. I'm convinced now, after posting here and getting some direction from Matthias, I believe it to be the thermal overload problem as described at the bottom of this page: http://www.loopers-delight.com/tools/echoplex/FAQ6.html Guess I've been thinking about it for a couple days as it involves clipping one of the pins off the EPROM I just got in the mail! - I'm gonna give it a try this evening, I'll let you know how it goes. Andy G