FT-990 Memory Problem

[W8UJX]

When I turn the memory select knob (MEM) on my FT-990 the channel number displayed will not increment or decrement correctly.  It will move from 1,2 3, back to ,2,4,5,7, back to 5 etc.  The jumps are random and occur whether I am advancing or decrementing the number.

I tried cleaning the switch with DeoxIT.  No improvement.

Any ideas?  Thanks.
Jerry, W8UJX

[Steve - K4HX]

Check to see if it's an optical encoder. If it is, DeOxit is of no use.

[W8UJX]

Thanks Steve.  I'll try to take the assembly apart.