This is the 3rd scope that I got this week. It had sticker saying that did not have vertical or horizontal deflection. The dot on the screen did not respond to changes on volt/div or time/div, but it did respond to the position knobs. I had repaired a few of this before so I thought should not be difficult to repair. Undressed the scope, checked the voltages just a tad low.
I started to trace back the horizontal deflection, from the pins that connect to the tube. Nothing, flat line. Move back a little, to a transistor. Nothing. Jump to another page of the manual, located other transistor in the path. Nothing. Decided to check the IC (U870) that controls the sweep and I have an empty socket.
I carefully looked at the parts in the manual and yes this is a proprietary IC. Quick search on the web it can be had for $50, more than double of what I paid for the scope. And if they took the IC from here, probably to donate to another scope tells me that this scope must have other problems.
Sorry for the long missive. Is there another solution instead of this IC? Is this scope just became parts scope? Ideas?