Hioki 8840 failure / power supply issue

[sqeezer]

I am a proud owner of a Hioki 8840 that is faulty. It starts up quickly to the boot splash screen and then freezes.
A quick measurement seems to indicate that the voltages are not properly present. The power supply is arranged in two stages, a switch mode power supply to break mains down to manageable voltages and a secondary DC2DC converter that diversifies into different voltages needed by both digital and analog part. The digital side (+5V) seems to be fine as the instrument boots up nicely. CPU/EPROMs seem happy. I have the hunch that the boot process is failing due to some hybrids not responding as a consequence of missing voltages.
The capacitors on the secondary quite convoluted DC2DC converter give me a ballpark of the voltages that should be there but are currently missing. E.g. I figured that a 24V output is not working. This is needed to drive the printer and supplying it externally seems to have no effect on the initial “stuck in boot splash” problem. I see some more candidates for failures, e.g. there is a +9V and a -9V present, but just one -15V, which could be a intentional but I would guess that there should be a +15V.

I tried to get support from Hioki. Their support points me to sending the unit in.

Is there a service manual for the Hioki 8840 or schematics?

Could someone supply the correct voltages/pins on the power connector of the main board?
(see white connector in the images with black markings, indicating ground pins)

The unplugged connectors are irrelevant to the initial problem (and voltage issues)