O.K
As I suspected ,the reading on R623 is indeed wrong,
there should be no DC current through it (hence no voltage on it).
Please take a good photo of of R623,C613,C617 and vicinity.
Please take a good photo, of the solder side of R623,C613,C617 and vicinity.
Could be dirt oxidation or corrosion .
If dirty clean it well.
If clean, take out C613(note it's polarization) and C617.
Power up and re-measure voltage between both legs of R623 if we get DCV of 0.0mv we have a bad cap ,
most probably the electrolytic C613.
At this stage,measure the voltage on both legs of R621 and trim it with VR601 to about DC 300mv.
OK with C613 out, R623 Reads 00.0mV
I took a photo of the reading of R621 in 200 mV range and in 2 V range.
I can only go up to about 60.0 on 200mV range. Should I use the 2 V range on my meter to trim the voltage?