SE analog board - L2 width control

[smrieck511]

I have several of these boards that work fine so I know how to adjust this control. One of the width controls (L2) has no effect no matter what. Checked and reflowed all the solder joints.

is this perhaps connected to a resistor that might be shot? thanks for any help.

 

[smrieck511]

it's had a full recap by the way. I replaced C15 no difference... R19 looks like it might have something to do with it?

 

[powellb]

I have this same problem. I have tested/replaced the resistors and caps in that horizontal control circuit to no effect. It is common for the L2 inductor to break internally (the very fragile internal ferrite coil). It seems the only fix is to find a donor board and replace the inductor. I have ordered a broken Mac Plus parts board. I'm hoping that its L2 is intact and works on the SE board. I'll report back when I get to it.