ESQ-1 power supply voltage question

Working on getting my plastic case ESQ-1 working again. The display is dead and I got a horrific buzz on the output when I first turned it on. I pulled the power supply and re-capped it. All the voltages are in range, except the Vbb output for the display. It reads under +20 VDC when it should be between +45 to +55. Are there other components that I could look at swapping out to correct this? Thanks for any help.

You can also check the 4 diodes in the middle of the power supply. CR7,CR8, CR9 and CR10. They are type 1N4004. Also there are 2 power transistors near those diodes.
Check the Vbb voltage with the power supply disconnected from the main board and display to make sure the voltage not loaded down from a problem on the display board.

Thanks, PPD. That’s what I was thinking. Already tested it unloaded. I’ll reply if I find anything.