I've just had a good look at the circuit, and I was mistaken about the +5V section... I didn't realise it was derived from the +90V rail.
OK, the parts below make up the +5V section:
C3 - 10uF 25V
C4 - 0.1uF
C5 - 10uF 100V
R105 - 22K
R106 - 47K
R114 - 33K
Q53 - MPSA42
Also, you'll need to check the transistors and resistors that control the display glass anodes:
Q46 -> Q52 - MPSA92
Q54 -> Q60 - MPSA42
R91 -> R97 - 10K
R98 -> R104 - 120R
R107 -> R113 - 10K
If all these test/measure OK, then you may have a problem with one of the display glasses themselves.
