the Test Points:
110v measures 101v
+5 measures 2.6v
+55 measures 47v
+15 measures 0v
-8 measures 0.6v
I looked at component # U4411 which is an OP AMP, the input voltage to PIN-8 is 3.6 - 4v where it should be 26v or so.
I bought a new OP AMP IC, TL082 (same pin out and hopefully close enough spec) it didn't work, the voltage on pin-8 is still ~4v
Because the +55v is more or less OK, I suspect that U4411 is OK.
I suggest that you put back the original.
The voltage at pin 8 of U4411 is significant.
On the schematic which I have just downloaded, it shows the voltage to be 22V.
The 22v is derived from the +55v line by a zener diode VR4608.
I suggest that you measure the resistor R4412, should be 4.7k.
You will probably have to disconnect one end of R4412 to get the correct resistance reading.
If R4412 is OK I suggest that the zener VR4408 is faulty.