Dont remember the vert on those but we did sell a ton of them.
Check for PC cons at vert IC very common on that
vintage Sony.
Most ran on +15 & -15 from the FBT be sure you have both.
If not will usually be the diode & low value resistor +- 1 ohm.
And as always electros but I would put them 3rd.
73 Zeno
