Heidenhain Nd710 powers supply section repair

[Pat P.]

I have a Heidenhain Nd710 that seems to have a blown power supply section. Been trying to trace the fault basically at the component level, but no luck!
The only voltage I am showing at the connector to the main board is 30v (which I am assuming is for the VFD). A good portion of the board is covered with silicone, so it's proved to be a little tricky. Is there any chance anyone has a schematic for this?

[Pat P.]

Actual power supply is a YCL NAD-16c.
Looks like might be a faulty smps controller chip KA3842A - Vref output on pin 8 is showing less than 1 volt, should be 5V.
I'll order one up and see if that fixes it.

[MadTux]

Fixed a Heidenhain Positip 850 with bad PSU some time ago, there the SMPS startup resistors were fried, so the chip didn't get the power for initial startup.

[Pat P.]

checked all of those, were fine. I think it may have been a power surge that took the IC out, I'll order a couple at $.40 each just in case.

[Pat P.]

Turned out all was due to a bad electrolytic cap. marked 82 uf, tested at 60uf and 37ohm esr. substituted 100uf and good to go!