Hello.
I have an old Tektronix 2236 with a focus problems.
Here, at link below, as you can see, the focus potentiometer is fully counterclockwise and the trace is blur:

http://picasaweb.google.com/116568688030447199475/DropBox?authkey=Gv1sRgCPzsm4302ZXSEw#5510425901585135602

Can you give me any aid?
And how to disassemble the circuit parts to have access in focus-circuit (R892, C893, Q885, etc.) in A1 main board ???

Thanks everyone!