Vintage Synth Repair

I've just refurbished my JX8P's power supply unit,
replacing all caps. I check the voltages and see
+14.40v and -14.40v instead of -15v and +15v.

The schematics shows a M5230L dual tracking regulator, two 
transistors and an array of resistors.

So far I replaced the regulator to no avail,
and verified the correct values of the various high precision 
resisotrs in the circuit, which are found to be ol.

I'm trying to figure out what could be causing this problem,
can anyone help ?....

Here's JX8P power supply schematics:
http://www.fileden.com/files/2006/10/13/285304/jx8p%20ps.JPG

..and here's M5230L datasheet:
http://www.ortodoxism.ro/datasheets/MitsubishiElectricCorporation/mXqy
yxt.pdf

Thanks in advance !